| 1 | Quadrature amplitude modulation (QAM) is a form of digital modulation where the digital information is ___ |
| 2 | In Binary Phase Shift Keying (BPSK) modulation is carried out in how many possible phases? |
| 3 | The most common form of MFSK uses tones of 16 frequencies and ___ |
| 4 | MFSK (multiple frequency shift keying) was originally used by ___ |
| 5 | MFSK (multiple frequency shift keying) is a signal modulation method in ___ |
| 6 | Nowadays, Multiple Frequency Shift Keying is mainly used by ___ |
| 7 | The way of representing a bit stream changing the bit changes the sign of ___ |
| 8 | In ___,the frequency of a constant amplitude carrier signal is switched between two values |
| 9 | ___ represents a method of reducing the bandwidth required for the transmission |
| 10 | What causes interference between channels, because of which orthogonality is ___ |
| 11 | The signal space of QASK consists of how many orthogonal ASK spaces? |
| 12 | The QASK modulator consists of two identical binary ASK modulators, driven by ___ |
| 13 | In QASK, how many identical carriers, shifted 90° with respect to each other, are modulated by two independent data streams, usually at the ___ |
| 14 | The M-PSK Modulator Baseband block modulates using the ___ |
| 15 | M-PSK modulation schemes do possess ___ |
| 16 | The efficient design of an RF amplifier with a sufficient linear range has ___ |
| 17 | In QPSK, the four angles are usually out of phase by ___ |
| 18 | Transitions in the data cause the carrier to shift by ___ |
| 19 | For a given bit-rate, what requires half the bandwidth of PSK and is widely used for this reason? |
| 20 | In the case of two possible phases shift the modulation will be ___ |
| 21 | In PSK, For a 0, a 0 degrees phase sine wave is ___ |
| 22 | Which of the below statements are correct? |
| 23 | Today the FSK technique is used in low rate asynchronous modems up to ___ |
| 24 | What is the term used to describe an FSK signal whose carrier frequencies are separated by ___ |
| 25 | Mathematically, the modulated wave y(t) can be shown as ___ |
| 26 | FSK describes the modulation of a carrier (or two carriers) by using a different frequency for ___ |
| 27 | In which technique the frequency of the carrier signal is changed according to the data?/ |
| 28 | Telephone lines limit amplitude changes to ___ |
| 29 | The main advantage of the ASK technique is ___ |
| 30 | What describes the technique the carrier wave is multiplied by the digital signal f(t)? |
| 31 | Modems with data rate up to what Kbps are available? |
| 32 | The technique that enables digital signals to be converted into analog signals is ___ |
| 33 | Digital information signals have the shape of ___ |
| 34 | In the case of telephone lines the usable bandwidth for ___ |
| 35 | Communication channels like telephone lines are usually ___ |
| 36 | The equipment used to convert digital signals into analogue format is ___ |
| 37 | The same techniques used to transmit analog signals are ___ |
| 38 | The techniques used to modulate digital information to make it transmissible via ___ |
| 39 | Even though analog communications are cheaper, digital communications ___ |
| 40 | Which modification of DM in which the step size is ___ |
| 41 | ___ is a waveform coding technique that attempts to code signals without any knowledge |
| 42 | Which theorem allows quantify the complexity of a given message source, and allows us to ___ |
| 43 | ASCII character would actually be transmitted using ___ |
| 44 | A-law requires ___ for a uniform PCM equivalent |
| 45 | Both A-law and U-law use a similar approach to ___ |
| 46 | A-law and u-law both break a dynamic range into a total of ___ |
| 47 | A-law standard is primarily used by ___ |
| 48 | U-law is used by ___ |
| 49 | Limiting the linear sample values to ___ magnitude bits |
| 50 | Which law are audio compression schemes (codecs) defined by Consultative Committee for International Telephony and Telegraphy (CCITT)? |
| 51 | What is the single most important factor that affectsvoice quality in uniform quantization? |
| 52 | Therefore, an increase in quantization noise degrades the quality of a ___ |
| 53 | ___ is the process of converting each analog sample value into a discrete |
| 54 | If an input analog signal is sampled 8000 times per second and each sample is given ___ |
| 55 | The process of digitizing analog voice signals is called ____ |
| 56 | After filtering and sampling (through PAM) an input analog voice signal, the next step is |
| 57 | Who discovered that the original analog signal can be reconstructed if enough number of samples are taken? |
| 58 | The analog voice signal can be sampled at a ___ |
| 59 | What moves at a constant frequency, known as the sampling frequency? |
| 60 | Sampling is accomplished by ___ |
| 61 | Which is the first process performed in analog-to-digital conversion? |
| 62 | A message signal originates from a ___ |
| 63 | What work using digital signals? |
| 64 | Analog signal required lesser ___ capacity than digital capacity |
| 65 | Transmitting and receiving analog signals is usually less ___ |
| 66 | Digital signal are based on ___ |
| 67 | In digital system, the systems are very ___ |
| 68 | By using error correcting and error detecting codes, we can improve the ___ |
| 69 | What can be transmitted using binary digits? |
| 70 | The major reason of growth of digital communication recently is the availability of ___ |
| 71 | In digital communications, transmission of information takes place in ___ |
| 72 | Data transmitted may be digital messages originating from a ___ |
| 73 | Corresponding demodulation is also known as ___ |
| 74 | According to the most common definition, both baseband and passband signals representing ___ |
| 75 | The passband modulation and the corresponding demodulation (also known as detection) is ___ |
| 76 | Digital transmission is the transfer of ___ |
| 77 | In digital communications, data is transmitted in the form of ___ |
| 78 | ___ is the physical transfer of data in the form of a digital bit stream over a point-to-point |
| 79 | A typical value of IF for an AM receiver is ___ |
| 80 | A disadvantage of which type of receivers is the possibility of spurious responses due to frequency conversion? |
| 81 | What is used for long distance telephone transmissions lines, as part of frequency-division multiplexing (FDM) technique? |
| 82 | Single-sideband modulation (SSB), which is a refinement of AM, helps in utilizing what more efficiently? |
| 83 | To generate and detect phase changes complex ___ |
| 84 | A modem is a contraction of the ___ |
| 85 | In which modulation, a signal is always present and loss of signal is easily detected? |
| 86 | Compared to what, FM has greater immunity to noise on transmission medium? |
| 87 | In digital communications, ___ involves modifying the amplitude |
| 88 | All the three modulation techniques employ a carrier signal which has ___ |
| 89 | What amounts to imposing a signal by altering the frequency which takes very high frequency to ___ |
| 90 | Amplitude modulation is simple to ___ |
| 91 | Demodulation is done in ___ |
| 92 | In communication engineering, the message signal (also called baseband signal) is basically voice, video, etc., is ___ |
| 93 | Under the Single-Sideband Modulation (SSB) technique, the one of the two carrier sidebands are ___ |
| 94 | AM receiver operates in ___ |
| 95 | Compared to the AM receiver, the tuning range of the incoming carrier frequencies for ___ |
| 96 | Since FM signal has a larger band width there is likelihood that more ___ |
| 97 | If the deviation is 40 kHz and the highest audio frequency is 10 kHz, the modulation ___ |
| 98 | In normal reception, FM signals are almost totally free from ___ |
| 99 | In radio and signal processing, heterodyning is the generation of new frequencies by ___ |
| 100 | ___ is the medium that transports the modulated signal to the receiver |
| 101 | In which year D.K. Weaver developed the third method of generating SSB? |
| 102 | Single-sideband modulation (SSB), which is a refinement of AM, helps to ___ |
| 103 | Generation of AM wave is done in how many parts? |
| 104 | Under the high level modulation, if the transmitter power is ___ |
| 105 | Amplitude modulation is rarely used individually as it is highly sensitive to ___ |
| 106 | Vestigial Side band transmission is usually found in ___ |
| 107 | ___ is the act of extracting or retrieving the original information bearing signal from a modulated carrier wave |
| 108 | What amounts to imposing a signal on the amplitude of a frequency? |
| 109 | For digital communications, this intelligence is in the form of ___ |
| 110 | Which methods are used to encode digital information in an analog communication system? |
| 111 | How many types of basic modulation techniques are there? |
| 112 | ___ which are also called baseband signals, are incompatible |
| 113 | Microwave radio is a form of radio transmission that uses ___ |
| 114 | Channel bandwidth may be simply defined as the size of the range of frequencies that can be transmitted through ___ |
| 115 | Noise degrades the quality of information and data by affecting data and all types of ___ |
| 116 | Channel noise is the unwanted electrical or electromagnetic energy that carries no data or information but interferes with ___ |
| 117 | In data communication, the signal has to travel through ___ |
| 118 | ___ is the change in shape or form of a signal when a signal travels through an electronic circuitry or a transmission medium |
| 119 | Which cable consists of two twisted-pair cables with one shield? |
| 120 | In which year IBM developed its own cabling system called the IBM Cabling System (ICS)? |
| 121 | A layer of dielectric (non-conductive) material such as ___ |
| 122 | What is a measure of the thickness of the conductor? |
| 123 | A UTP cable contains ___ |
| 124 | What was shown as a copper medium which was first used in ___ |
| 125 | How many categories of twisted pair cables are there? |
| 126 | In Asymmetric Digital Subscriber Lines (ADSL) technology, a new technique was ___ |
| 127 | A modem is a device that changes analog signals into ___ |
| 128 | Which substance is used for the insulation purposes? |
| 129 | The error rate of transmission and the electrical noise is ___ |
| 130 | Which term means that the signal is contained within an enclosed physical path? |
| 131 | Bounded media or wired transmission systems employ ___ |
| 132 | What travel through the air, and has no boundaries, hence called un-bounded transmission? |
| 133 | How many categories of media are there? |
| 134 | What travels through the medium? |
| 135 | Noise is one of the major sources of ___ |
| 136 | Media is the plural form of ___ |
| 137 | In information technology, a ___ is an element, such as optical fibre, through which a message is communicated? |
| 138 | Data is transmitted in one direction at a time, for example, a ___ |
| 139 | Data circuit terminating equipment is also known as ___ |
| 140 | In the year 1948, Claude Shannon worked for the Bell Telephone Company in which country? |
| 141 | The first communication satellite was launched during ___ |
| 142 | ASCII is a 7-bit code, which results in an upper limit of ___ |
| 143 | Extended Binary-Coded Decimal Interchange Code was developed in which year? |
| 144 | A telephone connection, therefore, is an analog connection from an end user to the nearest telephone company office ___ |
| 145 | A telephone is a user-end-instrument to send and receive voice frequency signals ___ |
| 146 | In which year, Alexander Graham Bell’s telephone experiments started the ___ |
| 147 | In which country is the Baud code sometimes known as the Murray Code? |
| 148 | Emile Baudot, a Frenchman, prepared a code in which year? |
| 149 | In data communication, there are data communication jargons to contend with ___ |
| 150 | Higher frequency signals offer greater ___ |
| 151 | A composite signal is defined as a signal made of many ___ |
| 152 | A bandwidth is directly proportional to the capacity of a signal to ___ |
| 153 | ___ is one in which all frequency components of a signal are integer multiples of one frequency |
| 154 | A continuous-time sinusoidal signal, in its most general form ___ |
| 155 | A continuous-time signal p(t) is said to be a ___ |
| 156 | The equipment required to convert digital data to ___ |
| 157 | A cable television (CATV) video channel is approximately of ___ |
| 158 | ___ means the facts information statistics or the like derived by calculation |
| 159 | ___ is the range of frequencies contained in a signal |
| 160 | What is the term for the amount of time taken by a signal for ___ |
| 161 | Who discovered that it is possible to decompose a ___ |
| 162 | The impulse signal is also called ___ |
| 163 | A signal is formally defined as a function of ___ |
| 164 | We can define a periodic function through ___ |
| 165 | The circuit may be a physical path comprising of ___ |
| 166 | ___ refers to a path between two or more points along which an electrical current flows |
| 167 | Computers are ___ |
| 168 | The electromagnetic sinusoidal (waveform) or sine wave can be ___ |
| 169 | In its native form, human speech is an oscillatory disturbance in the air, which varies in ___ |
| 170 | Information which is analog in its native form (audio and image) can ___ |
| 171 | Analog is best explained by the transmission of signal, such as ___ |
| 172 | What deals with data or information transmission? |
| 173 | Which process is used to smooth out the stream of 8,000 pulses per second into ___ |
| 174 | How many ways are there to communicate, display, store or manipulate information? |
| 175 | The digital signal is converted back to its analog form in how many steps? |
| 176 | The quantized samples are encoded into a digital bit stream consisting of series of ___ |
| 177 | Which step involves quantization of the amplitude of the incoming samples to one of 255 amplitudes on a quantizing scale? |
| 178 | According to the Nyquist theorem, the analog signal is ___ |
| 179 | The actual bandwidth of the filtered signal is 3100 Hz (3400–300) which is often known as ___ |
| 180 | The frequencies below ___ is filtered because they tend to involve mainly electrical noise |
| 181 | Filtering is applied to filter the frequencies below ___ |
| 182 | The PCM system employs how many steps to accomplish its job? |
| 183 | Bit rate is the number of bits transmitted ___ |
| 184 | Binary is two level signals signifying on or off and is represented as ___ |
| 185 | The simplest representation for a signal is to represent ___ |
| 186 | In digital signal, each pulse represents on or off a binary digit, which is popularly known as ___ |
| 187 | What does digital signal offer with respect to the distortion, attenuation and noise than analog system? |
| 188 | Nowadays, signal processing is often done after converting different signals into ___ |
| 189 | What are designed to set the channel accurately, adjust the volume, etc., by ___ |
| 190 | While designing which device one has to ensure that the signals are ___ |
| 191 | In sound generating machines the small voltages are produced by ___ |
| 192 | In full duplex, how many wires are needed to transmit data in different directions? |
| 193 | In which type, data is transmitted only in one direction; for example, TV or radio transmission? |
| 194 | Name the basic components of any communication system? |
| 195 | Which forms of signals are used to communicate, display, store and manipulate information? |
| 196 | What are the basic properties of any electrical signal? |
| 197 | In electric and electronic communications, all the audio, video and ___ |
| 198 | Which of the following is a function of e-mail system? |
| 199 | The frequency ranges from 300 KHz to 3 MHz is used for? |
| 200 | Radio communication frequencies ranges from? |
| 201 | Which layer functions as liaison between user support layers and network support layers? |
| 202 | What is the main function of transport layer? |
| 203 | In OSI network architecture, the dialogue control and token management are responsibilities of? |
| 204 | Demodulation is the process of? |
| 205 | HTTP refers to? |
| 206 | Error detection at the data link level is achieved by? |
| 207 | What protects the coaxial cable from noise? |
| 208 | Communication circuits that transmit data in both directions but not at the same time are operating in ___ |
| 209 | In the IEEE standards 802.5 standards is also called? |
| 210 | Switch is a Device of ___ Layer of OSI Model |
| 211 | Full Form of NIC? |
| 212 | Which of the following is an advantage to using fiber optics data transmission? |
| 213 | Which of the following does not allow multiple uses or devices to share one communication line? |
| 214 | Which of the following is a variation of FDM? |
| 215 | When displaying a web page, the application layer uses ___ |
| 216 | ATM (Asynchronous Transfer Mode) is fundamentally a ___ technology? |
| 217 | PGP is one of the protocols used to provide security at ____ |
| 218 | The Post Office Protocol is an ____ |
| 219 | Each IP address can identify the ___ |
| 220 | Coding schemes can be divided into two broad ___ |
| 221 | The Internet addresses are ___ bits in length in IPV4 addressing scheme |
| 222 | Data Link Control Protocol (HDLC) is implemented at the ___ |
| 223 | ___ is the process in which the receiver tries to guess the message by using redundant bits |
| 224 | The ___ layer provides a well defined service interface to the network layer |
| 225 | If there is only one station with a packet to send, this guarantees that there will ___ |
| 226 | With Slotted Aloha, a ___ sends out small clock tick packets to the outlying stations |
| 227 | A noise where foreign signal enters the path of the transmitted signal is ___ |
| 228 | The distance a simple signal can travel in one period is called ___ |
| 229 | The geostationary satellite used for communication systems ___ |
| 230 | Which of the following is required to communicate between two computers? |
| 231 | To connect a computer with a device in the same room, you might be ___ |
| 232 | Usually, it takes 10-bits to represent one character ___ |
| 233 | In CRC there is no error if the remainder at the receiver is ___ |
| 234 | Carrier is ___ |
| 235 | The slowest transmission speeds are ___ |
| 236 | ICMP (Internet Control Message Protocol) is ___ |
| 237 | A distributed network configuration in which all data/information pass through a ___ |
| 238 | Which of the following TCP/IP protocol is used for transferring electronic mail messages from one machine to another? |
| 239 | The term ‘duplex’ refers to the ability of the data receiving stations to echo back a ___ |
| 240 | The Internet Control Message Protocol (ICMP) ___ |
| 241 | Which of the following is not a disadvantage of wireless LAN? |
| 242 | Which of the following is used for modulation and demodulation? |
| 243 | How many digits of the DNIC (Data Network Identification Code) identify the country?/ |
| 244 | SMTP is used to deliver messages to ___ |
| 245 | SMTP defines ___ |
| 246 | A SMTP session may include ___ |
| 247 | An email client needs to know the ___ |
| 248 | Which one of the following protocol is used to receive mail messages? |
| 249 | Simple mail transfer protocol (SMTP) utilizes ___ |
| 250 | Three or more devices share a link in ___ |
| 251 | Dual-stack approach refers to ___ |
| 252 | The ___ field determines the lifetime of IPv6 datagram |
| 253 | These are the features present in ___ |
| 254 | IPv6 does not use ___ |
| 255 | In the IPv6 header, the traffic class field is similar to which field in the IPv4 header? |
| 256 | The header length of an IPv6 datagram is _____ |
| 257 | The size of IP address in IPv6 is ___ |
| 258 | Which of these is not applicable for IP protocol? |
| 259 | Which of the following field in IPv4 datagram is not related to fragmentation? |
| 260 | Which of the following is not applicable for IP? |
| 261 | In ___ resources are allocated on demand |
| 262 | As the resources are reserved between two communicating end ___ |
| 263 | The resources needed for communication between end systems are ___ |
| 264 | Method(s) to move data through a network of ___ |
| 265 | Most packet switches use this principle ___ |
| 266 | A local telephone network is an example of ___ |
| 267 | Expand WAN ___ |
| 268 | Data communication system within a building or ___ |
| 269 | Data communication system spanning states, countries, or the ___ |
| 270 | This topology requires multipoint connection ___ |
| 271 | In this topology there is a central controller or ___ |
| 272 | Physical or logical arrangement of ___ |
| 273 | Multiplexing technique that shifts each signal to a ___ |
| 274 | In TDM, the transmission rate of the multiplexed path is ___ |
| 275 | Multiplexing can provide ___ |
| 276 | If there are n signal sources of same data rate than ___ |
| 277 | Which multiplexing technique transmits digital signals? |
| 278 | Multiplexing is used in ___ |
| 279 | The sharing of a medium and its link by two or more devices is ___ |
| 280 | Geostationary satellites ___ |
| 281 | Radio channels are attractive medium because ___ |
| 282 | Fiber optics posses following properties ___ |
| 283 | Coaxial cable consists of ___ concentric copper conductors |
| 284 | Which of this is not a guided media? |
| 285 | Identify the incorrect statement ___ |
| 286 | FTP uses ___ parallel TCP connections to transfer a file |
| 287 | FTP is built on _____ architecture |
| 288 | Expansion of FTP is ___ |
| 289 | Telnet is ___ |
| 290 | ___ allows you to connect and login to a remote computer |
| 291 | The protocol used by Telnet application is ___ |
| 292 | If we want that a character be interpreted by the client instead of ___ |
| 293 | The entire hostname has a maximum of ___ |
| 294 | Electronic mail uses this Application layer protocol ___ |
| 295 | To deliver a message to the correct application program running on a host, the ___ |
| 296 | Which of the following is an application layer service? |
| 297 | Pick the odd one out ___ |
| 298 | Application layer offers ___ service |
| 299 | Which one of the following is not correct? |
| 300 | Which one of the following protocol delivers/stores mail to receiver server? |
| 301 | Application layer protocol defines ___ |
| 302 | Which one of the following allows a user at one site to ___ |
| 303 | The ___ translates internet domain and host names to IP address |
| 304 | Which one of the following is a transport layer protocol? |
| 305 | Transport layer protocols deals with ___ |
| 306 | Which one of the following is a version of UDP with congestion control? |
| 307 | Transmission control protocol is ___ |
| 308 | User datagram protocol is called connectionless because ___ |
| 309 | Which one of the following is a transport layer protocol used in internet? |
| 310 | Transport layer aggregates data from different applications into a ___ |
| 311 | The technique of temporarily delaying outgoing acknowledgements so that they ___ |
| 312 | Which one of the following is the multiple access protocol for channel access control? |
| 313 | Which one of the following is a data link protocol? |
| 314 | CRC stands for ___ |
| 315 | When 2 or more bits in a data unit has been changed during the ___ |
| 316 | Automatic repeat request error management mechanism is ___ |
| 317 | Header of a frame generally contains ___ |
| 318 | Which sublayer of the data link layer performs data link functions that ___ |
| 319 | Which one of the following task is not done by data link layer? |
| 320 | The data link layer takes the packets from ___ |
| 321 | Wireless transmission can be done via ___ |
| 322 | A single channel is shared by multiple signals by ___ |
| 323 | The physical layer translates logical communication requests from the ___ |
| 324 | Physical layer provides ___ |
| 325 | Which transmission media has the highest transmission speed in a network? |
| 326 | The physical layer concerns with ___ |
| 327 | Transmission data rate is decided by ___ |
| 328 | Which layer provides the services to user? |
| 329 | Which address identifies a process on a host? |
| 330 | Which layer is responsible for process to process delivery? |
| 331 | TCP/IP model was developed ___ |
| 332 | Which address is used in an internet employing the TCP/IP protocols? |
| 333 | Which layer links the network support layers and ___ |
| 334 | TCP/IP model does not have ___ |
| 335 | The OSI model has ___ |
| 336 | OSI stands for ___ |
| 337 | A ___ is a device that forwards packets between networks by processing |
| 338 | ICMP is primarily used for ___ |
| 339 | The network layer protocol o |
| 340 | In virtual circuit network each packet contains ___ |
| 341 | The 4 byte IP address consists of |
| 342 | Which one of the following is not a function of network layer? |
| 343 | The network layer concerns with ___ |
| 344 | In a horizontal-slot antenna, the polarization of the energy is radiated in what direction? |
| 345 | In a frequency-sensitive antenna, the physical length of ___ |
| 346 | What is/are the basic type(s) of antenna array(s) in common use? |
| 347 | In a delay-type lens, the amount of delay in the phase of the ___ |
| 348 | A lens antenna which accelerates some portion of ___ |
| 349 | In a lens antenna, what is the purpose of the collimating lens? |
| 350 | The parabolic reflector is often used because it produces ___ |
| 351 | Radar range is determined as a function of which of the following measures? |
| 352 | Surface angular measurements for antenna directivity in ___ |
| 353 | Directivity refers to which of the following properties of a radiated beam? |
| 354 | A standing-wave ratio (swr) describes which of the following quantities? |
| 355 | Power ratio is a term used to express what property of an antenna? |
| 356 | The PIN diode begins acting as a variable resistance at what minimum frequency? |
| 357 | A Schottky barrier diode has which of the following advantages over a ___ |
| 358 | In a point-contact diode, passing a large current from the catwhisker to the ___ |
| 359 | In an avalanche transit-time diode, what causes the ___ |
| 360 | Gallium-arsenide semiconductors begin to exhibit which of the ___micro |
| 361 | Bulk-effect semiconductors have what primary advantage over normal pn junction semiconductors? |
| 362 | In a nondegenerative parametric amplifier with a pump frequency of ___ |
| 363 | In a nondegenerative parametric amplifier, how does the pump frequency compare to ___ |
| 364 | How is amplification accomplished in the circuit? |
| 365 | What is the most important feature of the parametric amplifier? |
| 366 | Stability is a problem in which, if any, of the following tunnel-diode frequency converters? |
| 367 | In the reflection-type, circulator-coupled tunnel-diode amplifier ___ |
| 368 | Tuning a tunnel-diode oscillator by changing the capacitance of ___ |
| 369 | The tuned circuit in a tunnel-diode oscillator determines which of the following circuit values? |
| 370 | The tunneling action of the tunnel diode produces which of the following useful properties? |
| 371 | The crossed-field amplifier produces which of the following desirable ___ |
| 372 | A magnetron should be “baked in” under which of the following conditions? |
| 373 | Inductive tuning in a magnetron is accomplished by which of the following actions? |
| 374 | Magnetic lines of force passing between cavities are intercepted in ___ |
| 375 | The greatest power output is produced in what magnetron mode of operation? |
| 376 | In a magnetron, the total action of many electrons returning to ___ |
| 377 | Energy from working electrons is received by which of the following magnetron fields? |
| 378 | In the electron-resonance magnetron, the total electric field is ___ |
| 379 | In electron-resonance magnetrons, which of the following anode blocks is/are used? |
| 380 | In magnetrons, the effect of filament bombardment can be reduced by ___ |
| 381 | In a negative-resistance magnetron, which, if any, of the ___ |
| 382 | Magnetron oscillators are divided into what total number of classes? |
| 383 | The critical value of magnetic field strength in a magnetron causes ___ |
| 384 | In a magnetron, what causes the path of an electron to curve when it is ___ |
| 385 | What property in a magnetron is controlled by the cavities in the plate? |
| 386 | In a magnetron, the magnetic field between the plate and cathode serves what purpose? |
| 387 | A microwave tube that extracts energy from a wave that travels from the ___ |
| 388 | In a twt, what is the purpose of the attenuators along the helix? |
| 389 | Velocity modulation of the electron beam in a twt is achieved by what action? |
| 390 | In a twt, what is the primary purpose of the helix? |
| 391 | Which of the following twt characteristics makes it ideal for use as an rf amplifier? |
| 392 | The term “dBm” is based on what standard reference level? |
| 393 | The term “bel” is a unit of measurement that expresses ___ |
| 394 | In the higher modes, power and amplitude limitations in ___ |
| 395 | In a reflex klystron, the choice of operating mode is determined by ___ |
| 396 | A reflex klystron in which the constantspeed electrons remain in ___ |
| 397 | In a reflex klystron, the length of time a constant speed electron remains in ___ |
| 398 | In a reflex klystron, what type(s) of electrical charge, if any, does the repeller have? |
| 399 | The repeller of a reflex klystron replaces what component in other types of klystrons? |
| 400 | The bandwidth of a multicavity klystron can be increased by ___ |
| 401 | In a three-cavity klystron, what cavity, if any, contributes most to ___ |
| 402 | What is the purpose of applying a large negative pulse to ___ |
| 403 | In a klystron, the placement of additional cavities between the ___ |
| 404 | The input signal to a two-cavity klystron amplifier is ___ |
| 405 | A two-cavity klystron that has a feedback path from the catcher cavity to ___ |
| 406 | In a klystron, an ac potential is superimposed on the dc voltage that is applied to ___ |
| 407 | Which of the following electronic interactions is used in klystron operation? |
| 408 | The point in a stream of electron bunches at which the ___ |
| 409 | How is an electron affected, if at all, if it enters the buncher-grid gap when ___ |
| 410 | The alternate speeding up and slowing down of electrons in a beam that produces ___ |
| 411 | An electron that enters an electrostatic field and travels in the ___ |
| 412 | Which of the following properties of an electron is directly proportional to its velocity? |
| 413 | Moving tube electrodes further apart to decrease ___ |
| 414 | A decrease in efficiency in a conventional vacuum tube caused by ___ |
| 415 | Undesirable degenerative feedback in conventional vacuum tubes can be ___ |
| 416 | As the frequency in a conventional vacuum tube is increased, what is the ___ |
| 417 | The amount of rotation in a Faraday rotation type ___ |
| 418 | The energy in a ferrite attenuator that is attenuated is dissipated as ___ |
| 419 | Electrons in a ferrite can be caused to wobble on their axes by ___ |
| 420 | Electrons exhibit which of the following types of motion? |
| 421 | The hybrid ring is usually used as what type of device in radar systems? |
| 422 | Low power-handling capabilities and internal power losses are ___ |
| 423 | E-type and H-type junctions are combined in which of the following devices? |
| 424 | A waveguide junction in which the arm area extends from the ___ |
| 425 | What are the two basic types of waveguide T junctions? |
| 426 | An adjustable slug or screw placed in the area of maximum E lines in ___ |
| 427 | Tuning is the process of changing what property of a resonant cavity? |
| 428 | What factor(s) determines the primary frequency of a resonant cavity? |
| 429 | What property gives a resonant cavity a narrow bandpass and allows ___ |
| 430 | For a device to be considered a resonant cavity, it must ___ |
| 431 | The highest frequency at which a conventional circuit can oscillate is ___ |
| 432 | When the two portions of a reflected wave reach the pickup probe of ___ |
| 433 | What is the electrical distance between the two holes in a simple directional coupler? |
| 434 | What is the primary purpose of a directional coupler? |
| 435 | Internal arcing in a waveguide is usually a symptom of which of the following conditions? |
| 436 | What type of corrosion occurs when dissimilar metals are in contact? |
| 437 | In your waveguide inspections, you should be alert for which of the following problems? |
| 438 | A circular waveguide is normally used in a rotating joint because ___ |
| 439 | The choke joint is used for what purpose in a waveguide? |
| 440 | A flexible waveguide is used in short sections because of ___ |
| 441 | A waveguide bend which is in the E or H plane must be greater than ___ |
| 442 | Reflections will be caused by an abrupt change in ___ |
| 443 | A resistive load most often dissipates energy in which of the following forms? |
| 444 | A resistive device with the sole purpose of absorbing all the energy in ___ |
| 445 | For a waveguide to be terminated with a resistive load, that load must be ___ |
| 446 | A horn can be used as a waveguide termination device because ___ |
| 447 | A waveguide iris that covers part of both the electric and magnetic planes acts as ___ |
| 448 | A waveguide which is not perfectly impedance matched to its load is ___ |
| 449 | Increasing the size of the loop wire increases which of the following loop capabilities? |
| 450 | Loop coupling is most efficient when the loop is placed at ___ |
| 451 | Loose coupling is a method used to reduce the amount of ___ |
| 452 | To inject or remove energy from a waveguide, which of the following devices could you use? |
| 453 | With the mode description ___ |
| 454 | With a mode description of ___ |
| 455 | The field configuration in waveguides is divided into what two categories? |
| 456 | How is the cutoff wavelength for a circular waveguide figured? |
| 457 | The most efficient transfer of energy occurs in a waveguide in the what mode? |
| 458 | The various field configurations that can exist in a waveguide are referred to as ___ |
| 459 | The group velocity of a wavefront in a waveguide may be ___ |
| 460 | How does the group velocity of an electromagnetic field in ___ |
| 461 | If the wall of a wave-guide is perfectly flat, the angle of reflection is ___ |
| 462 | What, if anything, happens to the amplitude of the wavefronts within ___ |
| 463 | For an electric field to exist at the surface of a conductor, the field must have ___ |
| 464 | What minimum number of boundary conditions must be satisfied for ___ |
| 465 | H lines have which of the following distinctive characteristics? |
| 466 | A difference in potential across a dielectric causes which of the following fields to develop? |
| 467 | Which of the following fields is/are present in wave guides? |
| 468 | In practical applications, which of the following dimensions describes ___ |
| 469 | The cutoff frequency for a wave-guide is controlled by the physical dimensions of ___ |
| 470 | If frequency is decreased, what change, if any, will be required in ___ |
| 471 | The range of operating frequencies is determined by ___ |
| 472 | At very high frequencies, which of the following devices works best as an insulator? |
| 473 | At very high frequencies, ordinary insulators in ___ |
| 474 | Which of the following characteristics of a waveguide causes the lower-frequency limitation? |
| 475 | Which of the following dielectrics is used in waveguides? |
| 476 | In a coaxial line, the current-carrying area of the inner conductor is ___ |
| 477 | Copper losses are reduced by what physical property of waveguides? |
| 478 | The most efficient transfer of electromagnetic energy can be ___ |
| 479 | Coaxial lines are more efficient than two-wire lines at microwave frequencies for ___ |
| 480 | Microwave theory is based on the action of which of the following fields? |
| 481 | The portion of the electromagnetic spectrum which falls between ___ |
| 482 | What type of circuit can be used to convert from ppm to pdm for demodulation? |
| 483 | What type(s) of modulation is/are normally detected by first ___ |
| 484 | To detect pulse-duration modulation, the low-pass filter components must be ___ |
| 485 | When a pulse-duration modulated signal is ___ |
| 486 | What change must be made to the circuit to detect pulse-duration modulation? |
| 487 | Which, if any, of the following functions is the purpose of CR2? |
| 488 | To detect pulse-amplitude modulation, what value must the ___ |
| 489 | Which of the following circuits can be used as a communications pulse demodulator? |
| 490 | To demodulate a phase-modulated signal, which, if any, of the following ___ |
| 491 | ABOVE the center frequency of the hosted at received ___ |
| 492 | For plate current to flow, what must be the polarities of ___ |
| 493 | What type of tank circuit is the quadrature tank (L3 and C3)? |
| 494 | What tube pins connect to elements that perform in a manner similar to ___ |
| 495 | What components in the circuit are used to set the reference frequency for a |
| 496 | Which of the following circuit functions is performed by the gated-beam detector? |
| 497 | What is the minimum input voltage, in millivolts, required for a ratio detector? |
| 498 | What components help to reduce the effects of amplitude variations at the input of the circuit? |
| 499 | When operating BELOW resonance, what is the relationship of ___ |
| 500 | ABOVE resonance, both voltages ___ |
| 501 | At resonance, (a) will the charges on C3 and C4 be equal or ___ |
| 502 | At resonance, what relative amount of conduction takes place through ___ |
| 503 | At resonance, what is the phase relationship between tank current and primary voltage? |
| 504 | At resonance, what type of circuit does the tank circuit appear to be? |
| 505 | What circuit filtering function do R5, C6, and C7 provide? |
| 506 | To what frequency(ies) are (a) L1 and C1 and (b) L2 and C2 tuned? |
| 507 | Circuit operation BELOW resonance is represented by which of the following vector diagrams? |
| 508 | When the circuit is operating ABOVE resonance ___ |
| 509 | At resonance, what is the amplitude of ___ |
| 510 | To what frequency are C1/L1 and C2/L2 tuned? |
| 511 | In the figure, what is the purpose of Q1? |
| 512 | What is the function of C1 and R1? |
| 513 | What is the purpose of T2? |
| 514 | What type of Circuits is/are shown in the figure? |
| 515 | This detector circuit is used under which of the following circuit conditions? |
| 516 | What is the purpose of C4? |
| 517 | What circuit component acts as the load for the detected audio? |
| 518 | What type of detector represents the below figure? |
| 519 | A shunt diode circuit is used as a detector in which of the following instances? |
| 520 | What is the purpose of C2? |
| 521 | What is the purpose of C1 and L? |
| 522 | What type of detector is shown in the figure? |
| 523 | A detector uses which of the following signals to approximate the original waveform? |
| 524 | A circuit that is nonlinear, provides filtering, and is sensitive to ___ |
| 525 | Which of the following circuit functions does Q1 perform? |
| 526 | What component provides the feedback necessary for oscillations to occur? |
| 527 | What component controls the operating frequency of the detector? |
| 528 | The detector circuit in the figure uses the heterodyning principle to ___ |
| 529 | Assume that two signals are received, one at 500 kHz and ___ |
| 530 | To aid in distinguishing between two or more cw signals that are close to ___ |
| 531 | In the figure, L and C1 form a frequency selective network that serves what purpose? |
| 532 | In cw demodulation, the first requirement of the circuit is the ability to ___ |
| 533 | In a demodulator circuit, which of the following components is ___ |
| 534 | When a demodulator fails to accurately recover intelligence from a modulated ___ |
| 535 | The process of recreating the original modulating frequencies (intelligence) from ___ |
| 536 | Which of the following is a characteristic of a pcm system that makes ___ |
| 537 | A pcm system is capable of transmitting 32 standard levels that ___ |
| 538 | The process of arbitrarily dividing a wave into a series of ___ |
| 539 | A pfm transmitter transmits 10,000 pulses per second without ___ |
| 540 | Which, if any, of the following is the primary disadvantage of pulse-position modulation? |
| 541 | The same pulse characteristic is varied in which of the following types of pulse modulations? |
| 542 | What is the simplest form of pulse modulation? |
| 543 | To accurately reproduce a modulating signal in ___ |
| 544 | To transmit intelligence using pulse modulation, which of the ___ |
| 545 | Compared to a spark-gap modulator, the thyratron modulator exhibits ___ |
| 546 | The damping diode in a thyratron modulator serves which of the following purposes? |
| 547 | In a spark-gap modulator, what is the function of the pulse-forming network? |
| 548 | When pulse modulation is used for range finding in ___ |
| 549 | In pulse modulation, what term is used to indicate the ratio of ___ |
| 550 | Average power in a pulse-modulation system is defined as the |
| 551 | In a square-wave modulated signal, total sideband power is what percentage of the total power? |
| 552 | As the square wave modulating voltage is increased to the same amplitude as ___ |
| 553 | When a carrier is modulated by a square wave, what maximum number of ___ |
| 554 | Which of the following circuits is used to generate a phase-shift keyed signal? |
| 555 | When a carrier is phase-shift keying modulated ___ |
| 556 | Phase-shift keying is most useful under which of the following code element conditions? |
| 557 | The primary advantage of phase modulation over frequency modulation is ___ |
| 558 | A simple phase modulator consists of a capacitor in ___ |
| 559 | Compared to fm, increasing the modulating frequency in ___ |
| 560 | The frequency spectrums of a phasemodulated signal resemble the ___ |
| 561 | In phase modulation, (a) the AMPLITUDE of the modulating signal determines ___ |
| 562 | In a phase modulator, the frequency during the constant-amplitude portion of ___ |
| 563 | A 10 kilohertz, 10-volt square wave is applied as the phase-modulating signal to ___ |
| 564 | As the positive potential is increased on the cathode of ___ |
| 565 | A varactor is a variable device that acts as which of the following components? |
| 566 | To ensure the frequency stability of ___ |
| 567 | A multivibrator frequency modulator is limited to frequencies ___ |
| 568 | What type of circuit is used to remove the AM component in ___ |
| 569 | The reactance-tube frequency modulates the oscillator by which of the following actions? |
| 570 | With no modulating signal applied, a reactance tube has ___ |
| 571 | In a reactance-tube modulator, the reactance tube ___ |
| 572 | The spectrum of a 500 kilohertz fm modulated carrier has ___ |
| 573 | A 50-megahertz fm carrier varies between 49.925 megahertz and ___ |
| 574 | Modulation index may be figured by using which of the following formulas? |
| 575 | Frequencies that are located between adjacent channels to ___ |
| 576 | An fm transmitter has a 50-watt carrier with no ___ |
| 577 | The maximum deviation for a 1.5 MHz carrier is set ___ |
| 578 | A 1,000-hertz tone of a certain loudness causes the ___ |
| 579 | In an fm signal, (a) the RATE of shift is proportional to what characteristic of ___ |
| 580 | The “ratio of transmitted powers” provides what information? c |
| 581 | Fsk has which of the following advantages over cw? |
| 582 | In an fsk transmitter with a doubler and a tripler stage, the desired ___ |
| 583 | When the amount of oscillator frequency shift in an fsk transmitter is ___ |
| 584 | In an fsk transmitter, what stage is keyed? |
| 585 | Fsk is NOT affected by noise interfecrence for which of the following reasons? |
| 586 | If an fsk transmitter has a MARK frequency of ___ |
| 587 | In a frequency-shift keyed signal, where is the intelligence contained? |
| 588 | Frequency-shift keying is generated using which of the following methods? |
| 589 | Frequency-shift keying resembles what type of AM modulation? |
| 590 | In a cathode modulator, the modulating voltage is in series with ___ |
| 591 | A cathode modulator is used in which of the following situations? |
| 592 | The control-grid modulator is similar to which of the following modulator circuits? |
| 593 | Compared to a plate modulator, the control-grid modulator has ___ |
| 594 | Excessive modulating signal levels have which, if any, of the following effects on ___ |
| 595 | Which of the following inputs is/are applied to the grid of a control-grid modulator? |
| 596 | A control-grid modulator would be used in which of the following situations? |
| 597 | Plate- and collector-injection modulators are the most commonly ___ |
| 598 | In the collector-injection modulator, af and rf are heterodyned by ___ |
| 599 | In a plate modulator, with no modulation, how will the plate ___ |
| 600 | To achieve 100-percent modulation in a plate modulator, what maximum ___ |
| 601 | A plate modulator produces a modulated rf output by ___ |
| 602 | Heterodyning action in a plate modulator takes place in what circuit? |
| 603 | A final rf power amplifier biased for plate modulation operates in ___ |
| 604 | Which, if any, of the following advantages is a primary benefit of plate modulation? |
| 605 | Modulation produced in the plate circuit of the last radio stage of a system is ___ |
| 606 | The percent of modulation for a modulated carrier wave is figured using ___ |
| 607 | In a carrier wave with a peak amplitude of 400 volts and ___ |
| 608 | Overmodulation of an AM signal will have which, if any, of the ___ |
| 609 | If an rf carrier is 100 percent AM modulated, what will be the ___ |
| 610 | If a 1-megahertz signal is modulated by frequencies of ___ |
| 611 | If an 860-kilohertz AM signal is modulated by frequencies of ___ |
| 612 | What determines the bandwidth of an AM wave? |
| 613 | In an AM wave, where is the audio intelligence located? |
| 614 | If 750 hertz modulates a 100-kilohertz carrier, what would the ___ |
| 615 | When a 500-hertz signal modulates a 1-megahertz carrier, the 1-megahertz carrier and ___ |
| 616 | The vertical axis on a frequency spectrum graph represents ___ |
| 617 | The final audio stage in an AM transmitter is ___ |
| 618 | The intermediate power amplifier serves what function in a transmitter? |
| 619 | What are the two major sections of an AM transmitter? |
| 620 | What component in a magnetic microphone causes the lines of flux to alternate? |
| 621 | If you require a microphone that is lightweight, has high sensitivity, is ___ |
| 622 | The voltage produced by mechanical stress placed on certain crystals is ___ |
| 623 | A carbon microphone has which of the following advantages over other types of ___ |
| 624 | The action of the double-button carbon microphone is similar to ___ |
| 625 | What component in a carbon microphone converts a dc voltage into a varying current? |
| 626 | Which of the following is the schematic symbol for a microphone? |
| 627 | To change sound energy into electrical energy, which of the ___ |
| 628 | Which of the following combinations of frequency multiplier stages will ___ |
| 629 | Amplifier tubes are added to the output of a transmitter for which of the following reasons? |
| 630 | To prevent a transmitter from being loaded ___ |
| 631 | Which of the following advantages is a benefit of cw communications? |
| 632 | Transmitter machine keying was developed for which of the following purposes? |
| 633 | Interference detected by a receiver is often caused by the application and ___ |
| 634 | When keying a high-power transmitter, what component should ___ |
| 635 | To ensure frequency stability in a cw transmitter, you should NOT key what circuit? |
| 636 | What is the purpose of the key in a cw transmitter? |
| 637 | The method of rf communication that uses either the presence or ___ |
| 638 | Spectrum analysis is used to view which of the following characteristics of an rf signal? |
| 639 | For the heterodyning action to occur in a ___ |
| 640 | What effect, if any, does a nonlinear device have on a sine wave? |
| 641 | With a sine-wave input, how will the output compare to the input in ___ |
| 642 | Which of the following types of modulation is a form of amplitude modulation? |
| 643 | In rf communications, modulation impresses information on ___ |
| 644 | The ability of a circuit to faithfully reproduce the input signal in ___ |
| 645 | As the frequency of a signal is increased, what change can be noted about its wavelength? |
| 646 | What is the wavelength of a 1.5 MHz frequency? |
| 647 | An electromagnetic wavefront moves through free space at ___ |
| 648 | Which of the following waveform characteristics determines the wavelength of a sine wave? |
| 649 | Which of the following mathematical relationships do you use to figure the period of a sine wave? |
| 650 | The frequency of the sine wave is determined by which of the following sine-wave factors? |
| 651 | The degree to which a cycle has been completed at any given instant is ___ |
| 652 | The part of a sine wave that is above the voltage reference line is ___ |
| 653 | The trigonometric relationship for the sine of an angle in a right triangle is ___ |
| 654 | A rotating coil in the uniform magnetic field between ___ |
| 655 | Vectors are used to show which of the following characteristics of a sine wave? |
| 656 | When you use a vector to indicate force in ___ |
| 657 | You can communicate with others using which of the following transmissions mediums? |
| 658 | The action of impressing intelligence upon a transmission medium is ___ |
| 659 | Laser transmissions during adverse weather conditions experience ___ |
| 660 | Which of the following components is a close relative of the laser? |
| 661 | The principle of the laser is much like that of, which of the ___ |
| 662 | A laser operates in which of the following areas of the light spectrum? |
| 663 | What is the maximum number of channels available when you are ___ |
| 664 | When in the automatic mode of operation, the transmitter transmits ___ |
| 665 | What is the primary source of power for the cotransmitter? |
| 666 | What are the operating frequencies of the transmitter? |
| 667 | Search and rescue stations are divided into ___ |
| 668 | When designing portable and pack radios, which of the ___ |
| 669 | Portable radio sets are used primarily for ___ |
| 670 | Which of the following NTDS links, which one(s) is/are only used as ___ |
| 671 | The NTDS uses which of the following data transmission links? |
| 672 | Which of the following advantages, which one is ___ |
| 673 | A one-hop transmission of a tropo-scatter system can ___ |
| 674 | Horn-driven paraboloid antennas have which of the following characteristics? |
| 675 | In a line-of-sight communications system, propagation is ___ |
| 676 | Which of the following amplifiers, which one has ___ |
| 677 | The demodulation of ssb, cw, and fsk signals is ___ |
| 678 | The rejection of input frequencies above 900-kilohertz is performed by ___ |
| 679 | With one exception, the receiver has the same circuitry as ___ |
| 680 | Which of the following antenna arrays consists of ___ |
| 681 | Which of the following communications system ___ |
| 682 | The pre-ipa and ipa in an mf transmitter are which of the following types? |
| 683 | In an mf transmitter, the frequency generator is used during ___ |
| 684 | Satellite communications systems are being rapidly developed by ___ |
| 685 | What determines the length of time that a nonsynchronous satellite in ___ |
| 686 | The availability of a satellite to act as a relay station between ___ |
| 687 | The rf power output of a satellite communications system is ___ |
| 688 | Active communications satellite systems have ___ |
| 689 | A satellite communications system is limited by ___ |
| 690 | Which of the following statements best describes the advantage of ___ |
| 691 | An increase of invulnerability to jamming of ___ |
| 692 | Which of the following factors limits the reliability of ___ |
| 693 | When compared to hf communications, which of the following advantages are ___ |
| 694 | Which of the following terms, which one describes the period of ___ |
| 695 | Satellite down-link frequency variations occur most often from satellites in ___ |
| 696 | To establish radio contact with a satellite, an earth terminal must know ___ |
| 697 | What is the name of the table that provides coordinates of a satellite at specific times? |
| 698 | Locating a near-synchronous satellite is rather simple for which of the following reasons? |
| 699 | A typical shipboard receive-only satellite system uses ___ |
| 700 | Telemetery equipment used in satellite communications systems performs ___ |
| 701 | Which of the following functions is performed by the exciter stage of ___ |
| 702 | Why do satellite earth terminals require highly sensitive receivers? |
| 703 | One earth terminal antenna uses a ___ |
| 704 | Which of the following characteristics is a requirement for ___ |
| 705 | Why is satellite orientation in space so important? |
| 706 | What development in satellite communications improved ___ |
| 707 | Which of the following power sources is/are considered a practical choice for satellites? |
| 708 | There were many limitations that caused problems on ___ |
| 709 | In order to cover most of the earth except the ___ |
| 710 | A satellite orbiting with an angle of inclination of ___ |
| 711 | A satellite which has a flight path that does not coincide with ___ |
| 712 | As a reference, perigee and apogee are measured in ___ |
| 713 | What is the parameter in the orbit of a satellite that refers to ___ |
| 714 | When the period of an orbit is identical to ___ |
| 715 | Which of the following orbit parameters, which one describes the ___ |
| 716 | An earth terminal receives signals on what frequency? |
| 717 | Transmission of information to a satellite is done on what frequency? |
| 718 | There are two types of ___ |
| 719 | What artificial satellite is credited with starting the era of space technology? |
| 720 | You have been working on a piece of equipment and your eyes have been ___ |
| 721 | The greatest hazard from thermal effects appears to ___ |
| 722 | Which of the following methods of reducing rf burn hazards is ___ |
| 723 | Which of the following body organs, which are considered the most ___ |
| 724 | Shipboard receive systems are designed to include protective circuitry between ___ |
| 725 | Cross modulation is a form of emi where the desired carrier intermodulates with ___ |
| 726 | Which of the following categories of electromagnetic interference includes ___ |
| 727 | The sources of electromagnetic radiations that ___ |
| 728 | Which of the following terms, which one is defined as ___ |
| 729 | Scheduled maintenance in support of QMCS is designed to ___ |
| 730 | What one assumption may be made regarding all military radio transmissions? |
| 731 | Of the following fundamental requirements of ___ |
| 732 | Of the following terms, which one is primarily concerned with ___ |
| 733 | In a facsimile system, which of the following methods is ___ |
| 734 | Which of the following means is used to synchronize the ___ |
| 735 | The purpose of the phototube in facsimile equipment is to ___ |
| 736 | The scanning operation is accomplished in the facsimile transmitter by ___ |
| 737 | Which of the following facsimile transceiver operations consists of ___ |
| 738 | Weather charts and photographs are examples of ___ |
| 739 | In a 16-channel tty-multiplexing system, the maximum difference between ___ |
| 740 | By using frequency-division multiplexing, tty circuits may carry ___ |
| 741 | Frequency-division multiplexing systems transmit and ___ |
| 742 | How many times per cycle is a practical ___ |
| 743 | In time-division multiplexing, what drawback is ___ |
| 744 | In time-division multiplexing, assume that a 4,000-hertz tone is applied to ___ |
| 745 | What are the two methods of multiplexing? |
| 746 | The process of simultaneous transmission of several intelligible signals on ___ |
| 747 | In an afts transmit system, the conversion of dc signals into ___ |
| 748 | A comparator compares signal strength during ___ |
| 749 | In the radio-frequency-carrier shift system, translation of an rf signal to ___ |
| 750 | Cryptographic equipment performs which, if any, of the following functions? |
| 751 | In any switching operation between plugs and jacks of ___ |
| 752 | You are working with a teletypewriter patch ___ |
| 753 | Teletypewriter patch panels perform which of the following functions? |
| 754 | Which of the following teletypewriter equipment, which one is used to ___ |
| 755 | The keyer in a radio-frequency-carrier shift system is normally adjusted for ___ |
| 756 | In a radio-frequency-carrier shift system, what equipment is ___ |
| 757 | In a basic tone-modulated radio teletypewriter system, separation of ___ |
| 758 | A tone-modulated radio teletypewriter system uses what modulation method to ___ |
| 759 | To change an rf signal to do pulses for teletypewriter operation, you must ___ |
| 760 | Of the following equipment which one changes teletypewriter dc pulses to ___ |
| 761 | You are using neutral keying and the teletypewriter type ___ |
| 762 | The teletypewriter condition where current flow represents ___ |
| 763 | When you are referring to the unit of teletypewriter signaling ___ |
| 764 | Synchronous teletypewriter systems are characterized by ___ |
| 765 | In teletypewriter operation, what term defines the length of ___ |
| 766 | Which, if any, of the following modes of teletypewriter operation is ___ |
| 767 | When you are using the teletypewriter five-unit code, which of the ___ |
| 768 | When you are using the five-unit code in teletypewriter operation, what is ___ |
| 769 | The time interval between words when using the Morse code is ___ |
| 770 | Which of the following terms describe the time between ___ |
| 771 | A teletypewriter code signal consists of ___ |
| 772 | In a manual telegraph circuit, the only two ___ |
| 773 | Transmitting antenna patch panels are interlocked with the ___ |
| 774 | A receiving antenna patch panel serves which of the following functions? |
| 775 | The receiver demodulates and provides audio outputs for ___ |
| 776 | The full accuracy of the frequency standard is sacrificed when ___ |
| 777 | Adjacent-channel selectivity and image frequency suppression have ___ |
| 778 | You are using the cw mode of the ___ |
| 779 | The antenna coupler is pressurized with dry nitrogen for which of the following reasons? |
| 780 | Once tuned, the antenna coupler is able to ___ |
| 781 | Operator controlled tuning of the antenna coupler group by ___ |
| 782 | In some installations tuning must be done without the use of ___ |
| 783 | The rf amplifier receives digital tuning information that is ___ |
| 784 | The output power of the transmitter unit drives which of the following counits? |
| 785 | The impedance matching of equipment to transmission line is ___ |
| 786 | On a receiver transfer switchboard, each switch position is ___ |
| 787 | You are using a radio set control unit to ___ |
| 788 | When you are using a transmitter transfer switchboard ___ |
| 789 | In a basic communications voice system, which of the following ___ |
| 790 | For which of the following reasons do most ___ |
| 791 | Permanent magnet speakers respond quite well to ___ |
| 792 | When using the frequency synthesis process, a signal of the ___ |
| 793 | How is the long term stability and accuracy required of ___ |
| 794 | A change in oscillator frequency will change ___ |
| 795 | What is the phase relationship between the input signals fed to the diodes? |
| 796 | Automatic frequency control circuits are used in ___ |
| 797 | When the wiper of R1 is placed in the full ___ |
| 798 | A quartz crystal filter is used in a communications receiver to ___ |
| 799 | How does a receiver accomplish the squelch function? |
| 800 | What is the purpose of the squelch circuit in a receiver? |
| 801 | Which of the following types of agc voltage drives an amplifier toward cutoff? |
| 802 | AgC circuitry within a receiver uses a portion of ___ |
| 803 | To automatically compensate for input signal strength variations within a ___ |
| 804 | The amount of agc feedback depends on attaining ___ |
| 805 | If the agc diode shorts, which of the following actions would result? |
| 806 | The rf amplifier connected to your receiving antenna has ___ |
| 807 | Changes in receiver input strength due to ___ |
| 808 | Manual volume control of a receiver internally varies ___ |
| 809 | Manual gain lets you adjust a receiver for maximum sensitivity and ___ |
| 810 | A transmitter has a suppressed carrier frequency of ___ |
| 811 | Single sideband receivers use ___ |
| 812 | Ssb transmissions have which of the following characteristics when ___ |
| 813 | An FM signal has which of the following characteristics when ___ |
| 814 | There are electrical differences between ___ |
| 815 | Two or more circuits within a receiver are varied by ___ |
| 816 | Which of the following frequencies, which one is ___ |
| 817 | The process of heterodyning takes place in which of the following receiver circuits? |
| 818 | The IF frequency in a receiver is produced by which of the following methods? |
| 819 | When high fidelity is your prime consideration you should select ___ |
| 820 | How is a receiver’s ability to reject unwanted ___ |
| 821 | Overall sensitivity of a receiver is limited by which of the following factors? |
| 822 | Which of the following measurements provides an indication of ___ |
| 823 | The receiver action of converting electrical energy to ___ |
| 824 | When a receiver separates the audio frequencies from ___ |
| 825 | When a receiver picks one frequency out from ___ |
| 826 | A transmitted electromagnetic wave enters an antenna, induces a ___ |
| 827 | Operators of transmitters and receivers use a circuit to ___ |
| 828 | For ship-to-shore teletypewriter circuits, which of the ___ |
| 829 | When compared to a conventional AM signal, an ssb signal provides ___ |
| 830 | In a single-sideband transmitter, selection of ___ |
| 831 | When an AM signal leaves the antenna of ___ |
| 832 | Oscillator output frequencies are raised to usable values by ___ |
| 833 | If the fundamental frequency of an rf carrier is ___ |
| 834 | If an oscillator has a fundamental frequency of ___ |
| 835 | In an fm transmitter, a varicap performs which of the following functions? |
| 836 | In an AM transmitter, audio frequencies are converted into ___ |
| 837 | There are differences between low- and ___ |
| 838 | In a cw transmitter, a buffer stage performs which of the following functions? |
| 839 | A cw transmitter must contain which of the following components? |
| 840 | Cw transmissions have narrow bandwidths and ___ |
| 841 | Which of the following transmitter types, which are used for ___ |
| 842 | Which of the following switched networks extends tactical voice to ___ |
| 843 | Aid in restoring downed fleet communications channels is ___ |
| 844 | What communications link mode of operation provides ___ |
| 845 | Communications links have many modes of ___ |
| 846 | A complex of links make up a major communications ___ |
| 847 | Normally the transmission range of vhf is limited to ___ |
| 848 | What type of diversity uses physically separated transmit or ___ |
| 849 | Sending a message on several frequencies at once is an example of ___ |
| 850 | Hf communications over long-distance trunks, or links between ___ |
| 851 | For which of the following reasons does the Navy use ___ |
| 852 | Navy use of the low-frequency band is mainly for ___ |
| 853 | Vlf transmitters are used primarily for which of the cfollowing purposes? |
| 854 | Extremely low-frequency transmissions are primarily directed at ___ |
| 855 | What is the total number of frequency bands the military is ___ |
| 856 | When using the reference designator 1A6A4J6, what level does the ___ |
| 857 | When you use subdivisions to assign reference designators to ___ |
| 858 | What method is normally used to transmit graphs electronically? |
| 859 | You want to transmit high-speed automatic page or ___ |
| 860 | Tactical communications is usually considered as ___ |
| 861 | Radiotelegraph (cw) is valuable when communicating to, from, and ___ |
| 862 | Which of the following terms includes intelligence produced by ___ |
| 863 | What are the two types of electrical communications? |
| 864 | For naval communications to be effective, all involved must be ___ |
| 865 | Injury from X-rays would most likely result from which of the following actions? |
| 866 | For which of the following reasons do personnel sometimes develop ___ |
| 867 | Which of the following characteristics of cooling water for ___ |
| 868 | A radar cooling system has a low-flow alarm in ___ |
| 869 | Which of the following methods is used to cool radar system components? |
| 870 | Which of the following units may be available as ___ |
| 871 | The air control panel is designed to ___ |
| 872 | What is the normal source of dry air for a shipboard radar system? |
| 873 | If your equipment is missing a certain voltage ___ |
| 874 | Most primary shipboard ac distribution systems provide ___ |
| 875 | Which of the following conditions, which would be a ___ |
| 876 | The presence of standing waves on a transmission line indicates ___ |
| 877 | Which of the following methods is/are used to determine the effectiveness of a tr tube? |
| 878 | Tr recovery time places limits on which of the following quantities? |
| 879 | When expressing the sensitivity of a ___ |
| 880 | The ability of a receiver to detect weak signals can be ___ |
| 881 | Which of the following factors determines the overall ___ |
| 882 | Most transmitter power readings are referenced to ___ |
| 883 | Desirable transmitter output power characteristics include ___ |
| 884 | What constitutes the single most useful measurement you can ___ |
| 885 | Oscillations in an echo box are known as ___ |
| 886 | The echo box is a good instrument for measuring ___ |
| 887 | In a good spectrum curve the distance between ___ |
| 888 | An ideal radar frequency spectrum would be best described in ___ |
| 889 | What total number of modulating components are present in ___ |
| 890 | Which of the following statements describes a radar transmitter frequency spectrum? |
| 891 | If a transmitter carrier wave is modulated by ___ |
| 892 | If a fixed-frequency radar transmitter is found to be ___ |
| 893 | Airborne radars have unique physical design ___ |
| 894 | Feedhorn shadows can be eliminated by taking which of the following actions? |
| 895 | The directivity of a horn radiator is dependent on ___ |
| 896 | A broadside array causes maximum energy to be radiated perpendicular to ___ |
| 897 | Which of the following types of parabolic reflectors has ___ |
| 898 | What is the function of the hemispherical shield of the parabolic reflector? |
| 899 | To convert diverging waves into parallel waves, where must ___com |
| 900 | If the slant range and altitude of a target are ___ |
| 901 | An array of twelve dipoles are set in the same position as a ___ |
| 902 | If the vertical beam width of a radar antenna is ___ |
| 903 | Compared to omnidirectional antennas, directional antennas provide ___ |
| 904 | To read range directly, the range step is placed in what position relative to an echo pulse? |
| 905 | Range-markers are produced on the basis of which of the following timing constants? |
| 906 | When used with a ppi presentation, a range gate must have ___ |
| 907 | The range sweep in a range-gate generator is started at ___ |
| 908 | On the screen of a ppi scope, range markers appear as ___ |
| 909 | In a ppi scope that uses electromagnetic deflection, the amplitudes and ___ |
| 910 | Because the electromagnetic crt uses magnetic deflection, the ___ |
| 911 | Focusing is accomplished in an electromagnetic crt by ___ |
| 912 | Electromagnetic deflection is preferred over electrostatic deflection in ___ |
| 913 | Which of the following circuits produces currents that deflect the ___ |
| 914 | Pulses used to synchronize the ppi with the transmitter are ___ |
| 915 | Synchronization of events in ppi circuitry is of special importance for ___ |
| 916 | Own ship position is at the center of the scope in which of the following radar displays? |
| 917 | The rhi scope provides the operator with information concerning the ___ |
| 918 | The A-scope crt normally uses what type of sweep deflection? |
| 919 | To correctly represent the location of a target, a radar repeater must ___ |
| 920 | Which of the following quantities determines total distance represented on ___ |
| 921 | Of the following target parameters, which would most likely be ___ |
| 922 | Which of the following geometrical quantities is/are used as coordinates for radar displays? |
| 923 | What channel in a monopulse receiver is used as the reference channel? |
| 924 | The lin-log amplifier provides (a) a linear output voltage for ___ |
| 925 | The purpose of the mti system timing circuits is ___ |
| 926 | The amplitude of coherent video is determined by the ___ |
| 927 | In the mti system, what is the purpose of the coho lock pulse? |
| 928 | Delaying the received signals in the mti system permits them to ____ |
| 929 | The primary function of the mti system is to display ___ |
| 930 | In the input of the first video amplifier of ___ |
| 931 | In a radar receiver, which of the following purposes is |
| 932 | A radar receiver uses iagc for which of the following purposes? |
| 933 | Agc automatically adjusts the gain of the receiver by ___ |
| 934 | The detector in a radar receiver converts the IF pulses into what form? |
| 935 | The IF amplifier stage of a radar receiver determines ___ |
| 936 | The balanced transformer connected to the crystals of ___ |
| 937 | The resonant circuit at the output of an unbalanced crystal mixer serves ___ |
| 938 | Which of the following advantages is gained by using ___ |
| 939 | Which of the following devices would be used as a local oscillator in a radar receiver? |
| 940 | An efficient local oscillator must have which of the following characteristics? |
| 941 | What component in a receiver afc circuit produces an ___ |
| 942 | What section of a radar receiver usually determines the overall bandwidth? |
| 943 | The intermediate frequency is produced in what stage of a microwave receiver? |
| 944 | An overdriven amplifier stage in a receiver may cause ___ |
| 945 | An effective radar receiver should have a gain factor that is ___ |
| 946 | The maximum range at which a radar receiver can detect an object is ___ |
| 947 | Which of the following are requirements of a microwave receiver? |
| 948 | In a hybrid-ring duplexer, the fields at the entrance of ___ |
| 949 | The direct-coupled waveguide duplexer is connected to ___ |
| 950 | Indirectly coupled waveguide duplexers are normally connected to ___ |
| 951 | In a series-connected duplexer, what spark gap, if ___ |
| 952 | Atr tubes generally have a longer duty life than ___ |
| 953 | Keep-alive voltage is applied to the tr tube for ___ |
| 954 | What is the purpose of introducing water vapor into a tr tube? |
| 955 | Which of the following requirements is/are essential for proper tr spark gap operation? |
| 956 | The action of tr-atr circuits depends upon the impedance characteristics of ___ |
| 957 | Why is it desirable that the duplexer quickly connect the receiver to ___ |
| 958 | A defective duplexer in a radar will most likely cause damage to ___ |
| 959 | What is the primary function of the radar duplexing system? |
| 960 | A power-amplifier transmitter that transmits a broad band of ___ |
| 961 | Unwanted oscillations in an rf amplifier transmitter are ___ |
| 962 | Using a frequency synthesizer instead of a heterodyning mixer as ___ |
| 963 | The intermediate stages of a poweramplifier transmitter have ___ |
| 964 | Which of the following components determines the ___ |
| 965 | Which of the following tubes should be used as ___ |
| 966 | Compared to the keyed-oscillator transmitter, power-amplifier transmitters are ___ |
| 967 | Which of the following maximum tuning ranges is typical for a tunable magnetron? |
| 968 | Which of the following magnetron characteristics can be caused by ___ |
| 969 | Which of the following types of instability are common to magnetron oscillators? |
| 970 | What modulator circuit characteristic determines the ___ |
| 971 | The requirements of a modulator switch are to ___ |
| 972 | A pulse-forming network exhibits electrical behavior similar to ___ |
| 973 | What parameter, if any, of the output pulse from an ___ |
| 974 | The discharge pulse from the artificial transmission line causes ___ |
| 975 | A signal introduced at the input end of an artificial transmission ___ |
| 976 | Which of the following devices can be used as ___ |
| 977 | The modulator of a radar basically consists of ___ |
| 978 | Compared to the hard-tube modulator, the line-pulsing modulator has ___ |
| 979 | In order that nearby targets may be ___ |
| 980 | For proper operation of the magnetron, the modulator pulse must ___ |
| 981 | The transmitter range timing circuit must be triggered at ___ |
| 982 | The peak power of a transmitted rf pulse depends on which of the following factors? |
| 983 | A radar transmitter is triggered directly by high voltage pulses from what unit? |
| 984 | Which of the following oscillators generates sharp trigger ___ |
| 985 | The positive and negative output pulses of the astable multivibrator are ___ |
| 986 | When the master oscillator in a multivibrator timer is ___ |
| 987 | Which of the following circuits is used to ___ |
| 988 | Which of the following circuits converts square waves to positive and negative triggers? |
| 989 | Which of the following characteristics is NOT a requirement of ___ |
| 990 | The flyback retrace of a radar system indicator is prevented from ___ |
| 991 | Indicator sweep voltage in a radar is normally initiated at ___ |
| 992 | Which of the following radar indicator functions is/are controlled by ___ |
| 993 | A radar system in which timing triggers are determined by the ___ |
| 994 | Which of the following oscillators, used in a synchronizer to ___ |
| 995 | Which of the following oscillators may be used as the master oscillator in a radar system? |
| 996 | Which of the following classifications describes a radar system that ___ |
| 997 | Which of the following units of a radar system determines timing for all units of the radar? |
| 998 | Complete control of a beam-rider missile requires what minimum number of radar beams? |
| 999 | Which of the following characteristics is/are typical ___ |
| 1000 | When a fire-control radar antenna approaches the general direction of ___ |
| 1001 | Fire control radars must be directed to the general location of ___ |
| 1002 | The range capability of a 3D radar is limited by ___ |
| 1003 | Which of the following radars would most likely be used to ___ |
| 1004 | Which of the following types of radar provides ___ |
| 1005 | Which of the following are characteristics of a typical air-search radar? |
| 1006 | Long-range aircraft detection is provided by which of the following types of radar? |
| 1007 | Which of the following are typical characteristics of surface-search radars? |
| 1008 | Detection of surface and low-altitude air targets is the primary purpose of ___ |
| 1009 | For most military applications, which of the following radar systems is/are used? |
| 1010 | Which of the following JETDS classifications identifies ___ |
| 1011 | In Doppler radar, some definite relationship must exist between ___ |
| 1012 | Which of the following statements describes the advantage of ___ |
| 1013 | Frequency-modulated radars transmit a wave that continuously ___ |
| 1014 | Range information can be obtained in a Doppler radar by which of the following methods? |
| 1015 | Continuous-wave radar that uses the Doppler effect is ___ |
| 1016 | The frequency of the returned signal increases when a target is ___ |
| 1017 | In the cw radar transmission method, the Doppler effect provides ___ |
| 1018 | Monopulse receivers use what signal as a phase reference? |
| 1019 | In a monopulse scanning system, which of the following combinations ___ |
| 1020 | In a monopulse scanning system, which of the following ___ |
| 1021 | In a monopulse scanning radar, the relative position of ___ |
| 1022 | At any given distance from the antenna, the radar beam axis of ___ |
| 1023 | In a conical-scan antenna, nutation of the radar beam is ___ |
| 1024 | Which of the following methods can be used to achieve radar-beam scanning? |
| 1025 | In a single stationary-lobe scanning system, complete ___ |
| 1026 | The type and method of scanning used by a radar system depend upon ___ |
| 1027 | The sweep frequency of a radar indicator is determined by ___ |
| 1028 | To make amplification of received rf energy ___ |
| 1029 | Which of the following radar components allows the use of ___ |
| 1030 | What component of the transmitter supplies the ___ |
| 1031 | In a pulse radar system, what component controls timing throughout the system? |
| 1032 | In a pulse radar system, which of the following components should ___ |
| 1033 | Temperature inversions and/or moisture lapses in the atmosphere may ___ |
| 1034 | Refractions and speed changes are known to occur in ___ |
| 1035 | To detect nearby objects, the output pulse of ___ |
| 1036 | Which of the following factors has/have the greatest effect on ___ |
| 1037 | The width of a radar beam and range to a detected object are ___ |
| 1038 | What is the approximate range resolution (in yards) of a radar set with a ___ |
| 1039 | Target resolution is the ability of a radar to distinguish between ___ |
| 1040 | Altitude- or height-finding radar systems require a beam with ___ |
| 1041 | The relative bearing of a radar echo is measured with respect to ___ |
| 1042 | A radar set with a prf of 1,000 pps and an antenna rotation rate of ___ |
| 1043 | What is the maximum radar horizon distance for a radar set with ___ |
| 1044 | For a radar set with a pulse width of 25 microseconds and ___ |
| 1045 | What is the pulse-repetition time (in microseconds) for this radar set? |
| 1046 | What is the peak power (in kilowatts) for this radar set? |
| 1047 | Which of the following formulas can be used to compute the duty cycle of a radar set? |
| 1048 | What type of transmitter power is measured over a period of time? |
| 1049 | Which of the following terms describes radar returns ___ |
| 1050 | Pulse-repetition time is described as ___ |
| 1051 | Which of the following characteristics of a radar system determines the ___ |
| 1052 | Of the following radar characteristics, which has NO effect on maximum range capability? |
| 1053 | The minimum range of a radar depends on the length of ___ |
| 1054 | For an object that is detected 15 miles from ___ |
| 1055 | Electromagnetic energy travels through air at approximately what speed? |
| 1056 | The elevation angle to the target is the angle between which of the following references? |
| 1057 | What radar measurement of an object is referenced to true north? |
| 1058 | Radar uses what form of energy to detect ships, planes, and land masses? |
| 1059 | When installing fiber optic cables aboard Navy ___ |
| 1060 | A fiber optic cable plant consists of which of the following parts? |
| 1061 | Analog transmission would most likely be used in ___ |
| 1062 | The typical method of source modulation for most analog fiber optic systems is ___ |
| 1063 | An analog signal is defined as which of the following signals? |
| 1064 | When compared to analog transmission, digital systems can ___ |
| 1065 | A digital signal can be defined as which of the following signals? |
| 1066 | What are the two basic classifications of fiber optic links? |
| 1067 | In what topology is each equipment connected to a common center hub? |
| 1068 | What topology consists of equipments attached to one another in a closed loop? |
| 1069 | What topology consists of a transmission line that branches or splits? |
| 1070 | What topology consists of a single transmission line that is ___ |
| 1071 | What type of fiber optic link is the basic building block of all fiber optic systems? |
| 1072 | What type of fiber optic link consists of two ___ |
| 1073 | For which of the following applications would an APD rarely be used? |
| 1074 | For which of the following applications would a transimpedance amplifier typically be ___ |
| 1075 | Compared to a high-impedance amplifier, a transimpedance amplifier provides ___ |
| 1076 | Which of the following are basic types of preamplifiers used in typical fiber optic receivers? |
| 1077 | Which of the following types of noise are introduced by the fiber optic receiver? |
| 1078 | In a fiber optic system, which of the following is NOT a typical source of noise? |
| 1079 | What action, if any, will maximize the sensitivity of a fiber optic receiver? |
| 1080 | In a fiber optic receiver, what is the dominant contributor of electrical noise? |
| 1081 | The gain of an APD can be changed in what way? |
| 1082 | When compared to the reverse-bias voltage of ___ |
| 1083 | Reverse-biased photodetectors are highly linear devices with respect to ___ |
| 1084 | What is the name of the current produced by a photodiode when ___ |
| 1085 | A PIN photodiode usually operates in what way? |
| 1086 | The responsivity of an optical detector is constant over ___ |
| 1087 | The term detector responsivity has which of the following meanings? |
| 1088 | Which of the following terms is defined as the current produced by an optical detector because of ___ |
| 1089 | Which of the following factors does NOT affect the amount of ___ |
| 1090 | In fiber optic systems, what are the principal types of detectors used? |
| 1091 | Which of the following attributes is NOT a desirable attribute of an optical detector? |
| 1092 | The term dynamic range has which of the following meanings? |
| 1093 | The term receiver sensitivity has which of the following meanings? |
| 1094 | Which of the following is NOT a typical part of a fiber optic receiver? |
| 1095 | Which of the following fiber optic components is responsible for converting the ___ |
| 1096 | In shipboard applications with ___ |
| 1097 | In shipboard applications with moderate data rates ___ |
| 1098 | Which of the following are possible transmitter package types used in ___ |
| 1099 | Which of the following types of transmitters are typically the most expensive? |
| 1100 | For fiber optic transmitters, which of the following are typical output interfaces? |
| 1101 | For lasers that are to be operated under widely changing thermal ___ |
| 1102 | What kind of circuitry do most lasers have that compensates for ___ |
| 1103 | Which of the following types of sources have very similar semi-conductor designs? |
| 1104 | Which of the following types of sources is typically the most temperature sensitive? |
| 1105 | Transmitters containing what source type, if any, will typically require the ___ |
| 1106 | What does the term lasing threshold mean? |
| 1107 | Which of the following definitions best describes the term laser mode? |
| 1108 | Compared to SLEDs, ELEDs have all except which of the following properties? |
| 1109 | In low and moderate data rate applications, which of ___ |
| 1110 | Which of the following components is NOT one of the basic types of ___ |
| 1111 | In an optical source, the input electrical energy is converted to ___ |
| 1112 | Stimulated emission is the random generation of ___ |
| 1113 | Lasers produce light by what process? |
| 1114 | LEDs produce light by what process? |
| 1115 | What are the two most common semiconductor materials used in ___ |
| 1116 | What is it called when the fiber end face is directly placed over the source emitting region? |
| 1117 | Relevant optical power does NOT depend on which of the following factors? |
| 1118 | All of the light emitted by a semiconductor laser or LED is ___ |
| 1119 | Semiconductor lasers emit which of the following kinds of light? |
| 1120 | Semiconductor LEDs emit which of the following kinds of light? |
| 1121 | Incoherent light has what type of lightwaves? |
| 1122 | Fiber optic communication systems typically operate in what three wavelength windows? |
| 1123 | Which of the following properties are NOT desired properties of an optical source? |
| 1124 | An optical source has which of the following functions? |
| 1125 | Which of the following items is/are part of a fiber optic transmitter? |
| 1126 | What is the function of a fiber optic transmitter? |
| 1127 | During the measurement of the link’s output optical ___ |
| 1128 | When using a light source and a power meter to ___ |
| 1129 | When a point defect (a connector or a splice) exhibits an apparent gain in ___ |
| 1130 | OTDR measurements should be performed in each direction and ___ |
| 1131 | When the distance between the ends of a fiber is measured with ___ |
| 1132 | When fiber attenuation is measured with an OTDR, the end cursor, Z2, should be ___ |
| 1133 | When fiber attenuation is measured with an OTDR, the ___ |
| 1134 | When OTDR measurements are made, a dead zone fiber is used for what reason? |
| 1135 | The initial pulse (or spike) at the beginning and at most connections in ___ |
| 1136 | An OTDR should not be used to measure optical fibers or ___ |
| 1137 | Measurements made with an optical time domain reflectometer are ___ |
| 1138 | Field loss measurements are made by using which of the following test equipment? |
| 1139 | Some properties may change during installation; therefore, they are ___ |
| 1140 | The return loss of a fiber optic component is which of the following measurements? |
| 1141 | Insertion loss is determined by which of the following techniques? |
| 1142 | The mode field diameter of a single mode fiber relates to which of the following factors? |
| 1143 | The numerical aperture of a multi- mode fiber is best described by which of the following definitions? |
| 1144 | The far-field power distribution describes the emitted power per ___ |
| 1145 | The fiber far-field is which of the following regions? |
| 1146 | The fiber near-field is which of the following regions? |
| 1147 | The core diameter of a multimode fiber is defined by which of the following measurements? |
| 1148 | Cladding diameter, cladding noncircularity, core-cladding concentricity ___ |
| 1149 | End users perform fiber geometry measurements for which of the following reasons? |
| 1150 | Why does chromatic dispersion occur? |
| 1151 | Modal bandwidth is normally given in what units? |
| 1152 | The fiber bandwidth (-3 dB) is defined as the lowest frequency at ___ |
| 1153 | In a fiber, the intermodal (modal) dispersion is greatest under what condition? |
| 1154 | The spreading of a light pulse as it travels along the fiber is caused by what mechanism? |
| 1155 | When the cutoff wavelength is reached, why does ___ |
| 1156 | Determining the cutoff wavelength of a single mode fiber involves ___ |
| 1157 | What is the wavelength called over which the fiber will propagate only one mode? |
| 1158 | To remove high-order modes in ___ |
| 1159 | What is a mode filter? |
| 1160 | In what part of the fiber does an underfilled launch concentrate most of the optical power? |
| 1161 | What does the term overfilled launch mean? |
| 1162 | For single mode fiber, what method is typically used to ___ |
| 1163 | Launch conditions in an attenuation measurement are important to ___ |
| 1164 | Which of the following are considered launch conditions? |
| 1165 | In laboratory fiber attenuation measurements, the output optical power of ___ |
| 1166 | Standard test methods used for testing fiber optic components or ___ |
| 1167 | End users should measure some component parameters after installation of ___ |
| 1168 | End users should measure some component parameters upon ___ |
| 1169 | Manufacturers should measure some component parameters during ___ |
| 1170 | An optical coupler has several input ports and several ___ |
| 1171 | An optical coupler has one input port and several ___ |
| 1172 | An optical coupler has two input ports and ___ |
| 1173 | An optical coupler has one input port and ___ |
| 1174 | Active fiber optic couplers are called active fiber optic couplers for ___ |
| 1175 | Fiber optic couplers attenuate the optical signal much more than ___ |
| 1176 | In a heavy-duty connector, what are the two types of terminals called? |
| 1177 | A standard connector for Navy heavyduty applications is of which of the following styles? |
| 1178 | Light-duty connectors are intended for use in all but which of the following locations? |
| 1179 | The standard connector for Navy lightduty applications is of which of the following styles? |
| 1180 | In ceramic ferrules, the center hole is created by which of the following processes? |
| 1181 | Single fiber butt-jointed connections generally consist of which of the following parts? |
| 1182 | What are the two basic types of fiber optic connectors? |
| 1183 | The total loss of a fiber optic connector should always remain ___ |
| 1184 | Fusion splicing is not recommended for Navy use for ___ |
| 1185 | The basic process used in making fusion splices is which of the following methods? |
| 1186 | The assembly of a rotary splice is which of the following actions? |
| 1187 | For shipboard applications, which of the following types of splices is recommended? |
| 1188 | What are the two basic categories of fiber splices? |
| 1189 | Fiber optic splices are typically used in which of the following conditions? |
| 1190 | In Navy fiber optic applications, losses from fiber mismatches are ___ |
| 1191 | The connector end face should be inspected for ___ |
| 1192 | To remove most of the surface imperfections introduced in ___ |
| 1193 | The fiber cleaving process includes which of the following actions? |
| 1194 | Single mode fibers are less sensitive to alignment errors than ___ |
| 1195 | For mating fibers to touch when a connector is ___ |
| 1196 | Which of the following conditions is NOT a form of poor fiber alignment? |
| 1197 | A main source of extrinsic coupling loss in fiber to fiber connections is ___ |
| 1198 | In connections that have an air gap, the reflective losses can be ___ |
| 1199 | An intrinsic coupling loss may be caused by which of the following conditions? |
| 1200 | The loss in optical power through a connection is described by what relationship, if any? |
| 1201 | Coupling loss in a fiber optic connection may be caused by which of the following conditions? |
| 1202 | The distribution or combination of optical signals among fibers uses ___ |
| 1203 | Easy coupling and uncoupling of optical fibers are allowed by ___ |
| 1204 | A fiber optic connection that is typically intended to be permanent is what type, if any? |
| 1205 | A particular fiber optic cable design has the highest fiber count possible in ___ |
| 1206 | The only advantage of the stranded cable design over the ___ |
| 1207 | When compared with other cable designs, the OFCC fiber optic cable has ___ |
| 1208 | For low-density fiber Navy ship- board applications, which cable designs, if any, are preferred? |
| 1209 | Most commercial fiber optic cable jacket materials are suitable for ___ |
| 1210 | In the materials of a Navy shipboard fiber optic ___ |
| 1211 | Navy shipboard fiber optic cables should NOT contain ___ |
| 1212 | The fiber buffer performs which of the following functions? |
| 1213 | Properly designed optical cable structures perform which of the following functions? |
| 1214 | Most fiber optic cable structures contain which of the following items? |
| 1215 | To protect the fiber from contaminants in the ___ |
| 1216 | The process used in drawing the fiber is best described by which of the following statements? |
| 1217 | In making a preform, layers of glass powder are deposited on the ___ |
| 1218 | In the fabrication of silica optical fibers, which of the following processes may be used? |
| 1219 | The use of plastic-clad silica and all plastic fibers has what primary drawback? |
| 1220 | Fibers are single mode at a particular wavelength only when ___ |
| 1221 | For wavelengths greater than its cutoff wavelength, a typical single mode fiber is ___ |
| 1222 | What are the two basic types of single mode step-index fibers? |
| 1223 | The attributes of the 62.5/125- mm fiber do NOT include which of the following factors? |
| 1224 | The multimode graded-index fiber that has the best ___ |
| 1225 | A step-index multimode fiber and a graded-index multimode fiber have ___ |
| 1226 | In multimode fiber, all light rays have to propagate all of ___ |
| 1227 | For a multimode graded-index fiber, the numerical aperture is ___ |
| 1228 | In multimode graded-index fibers, is the index of refraction of ___ |
| 1229 | Compared to multimode step-index fibers, do ___ |
| 1230 | Elements other than silicon and oxygen are added to ___t |
| 1231 | Which of the following multimode fiber core sizes is NOT a standard commercial fiber size? |
| 1232 | In a graded-index fiber, the refractive index profile of the fiber core is ___ |
| 1233 | In a step-index fiber, the refractive index profile of the fiber core has which of the following characteristics? |
| 1234 | When different colors of light travel through the fiber at ___ |
| 1235 | Only in multimode fibers does which of the following types of dispersion occur? |
| 1236 | A radius of curvature is larger than the fiber diameter in ___ |
| 1237 | Which type of scattering loss is proportional to the reciprocal of ___ |
| 1238 | Increased extrinsic absorption at 950 nm, 1,250 nm, and 1,383 nm is ___ |
| 1239 | Glass optical fibers have low loss between the infrared and ___ |
| 1240 | Attenuation is specified in what units? |
| 1241 | The loss of optical power as light travels along ___ |
| 1242 | System performance is affected most by which of the following fiber properties? |
| 1243 | Compared to single mode fibers, multimode fibers have which of the following advantages? |
| 1244 | The lowest signal loss and the highest bandwidth are ___ |
| 1245 | Compared to multimode fibers, single mode fibers have ___ |
| 1246 | What are the two basic types of fibers? |
| 1247 | Compared to a low-order mode, the electrical and magnetic fields of ___ |
| 1248 | High-order modes cross the axis of the fiber at steeper angles than ___ |
| 1249 | Electromagnetic wave behavior is used to describe the propagation of ___ |
| 1250 | A skew ray is which of the following types of rays? |
| 1251 | The fiber NA relates to which of the following characteristics? |
| 1252 | What is the definition of a bound ray? |
| 1253 | The cladding performs all except which of the following functions? |
| 1254 | What are the three basic parts of an optical fiber? |
| 1255 | Total internal reflection occurs at which of the following angles? |
| 1256 | The relationship between the incident rays and the refracted rays at |
| 1257 | How does the speed of light in the fiber compare to the speed of light in the air? |
| 1258 | Light is transmitted along an optical fiber by what two methods? |
| 1259 | When light falls on a piece of black paper, what happens to most of the light? |
| 1260 | What is another word for diffused? |
| 1261 | If a light wave passes from a less dense medium to ___ |
| 1262 | A light wave passes from one medium into another medium with ___ |
| 1263 | A light wave is incident on a ___ |
| 1264 | What is the name of the law that states “The angle of incidence is equal to the angle of reflection”? |
| 1265 | What are light waves called that strike a surface but are neither transmitted nor absorbed? |
| 1266 | Which of the following objects is NOT an example of a luminous source? |
| 1267 | Which of the following substances is an example of an opaque substance? |
| 1268 | What does an opaque substance do when light rays fall on it? |
| 1269 | Which of the following substances is a good example of a transparent substance? |
| 1270 | Which of the following substances is a good example of a translucent substance? |
| 1271 | What does a translucent substance do to light rays that fall on it? |
| 1272 | What does a transparent substance do to light rays that fall on it? |
| 1273 | Which of the following factors is a description of transverse wave motion? |
| 1274 | Light exhibits what kind of wave motion? |
| 1275 | To describe the nature of light, which of the following ways can be used? |
| 1276 | The following factors, which ones are advantages of fiber optic systems? |
| 1277 | The following advantages, which one does NOT apply to fiber optics? |
| 1278 | Fiber optics is being used in which of the following types of applications? |
| 1279 | What multimode fiber properties help reduce connection losses? |
| 1280 | Compared to multimode fibers, single mode fibers tend to ___ |
| 1281 | What was the first light source developed that could be easily coupled into a fiber? |
| 1282 | Extremely high losses occurred in early fibers because of which of the following conditions? |
| 1283 | Besides the transmitter, the optical fiber, and ___ |
| 1284 | What are the two types of optical detectors? |
| 1285 | Noise has what effect, if any, on the quality of a signal? |
| 1286 | What are the two parts of a fiber optic receiver? |
| 1287 | The fiber optic receiver performs which of the following functions? |
| 1288 | What fiber mechanisms weaken and distort the optical signal launched into the fiber? |
| 1289 | The optical source performs which of the following functions? |
| 1290 | Fiber optic systems use what two types of optical sources? |
| 1291 | The fiber optic transmitter has which of the following functions? |
| 1292 | What are the three parts of a fiber optic data link? |
| 1293 | Fiber optics uses what medium to send information? |
| 1294 | About the Electronics & Communication MCQ category |
| 1295 | The datarate R of a digital communication system is about how ___ |
| 1296 | Which of the statement is correct? |
