Top 250 Electronic Circuits Objective Questions and Answers

In this article, we published the top 250 electronic circuits objective and answers for electrical and instrumentation engineers.

Electronic Circuits Objective Questions

Top 250 Electronic Circuits Objective Questions and Answers

The below list provides all the multiple-choice questions (MCQ) related to electronic circuits.

Answers are available at the bottom of the article.

1. Practically, the voltage gain of an amplifier is expressed

A)As a whole number
B)In dB unit
C)In volts unit
D)As an absolute value

2. If a transistor is operated in such a way that output current flows for 160 degrees of the input signal, then it is ​ _____ operation.

A)Class B
B)Class C
C)Class A
D)Class AB

3. The voltage gain of a common collector configuration is

A)Zero
B)Moderate
C)Very high
D)Unity

4. The gain of an amplifier is expressed in dB units because

A)Calculations become easy
B)It is the most appropriate unit
C)It is a simple unit
D)Human ear response is logarithmic

5. What is the phase difference between voltage across collector load and signal voltage in a common emitter amplifier?

A)180°
B)270°
C)
D)90°

6. A pair of filter common on high fidelity system which separate audio frequency band signals into two separate groups, where one is fed to the tweeter and the other to the woofer is called

A)Equalizer
B)Synthesizer
C)Cross over network
D)Hybrid

7. Which is not a basic BJT amplifier configuration?

A)Common-base
B)Common-drain
C)Common-collector
D)Common-emitter

8. An amplifier with efficiency of 85% is likely to be

A)Class B
B)Class A
C)Class C
D)Class AB

9. Minimum interference with frequency response can be given by

A)Transformer coupling
B)Instrumentation and control
C)Direct coupling
D)RC coupling

10. The general characteristics of a common base amplifier are

A)None of the answers
B)High voltage, high current gain, high power gain and low input resistance
C)Low voltage gain, high current gain, very high power gain and low input resistance
D)High voltage gain, low current gain, high power gain and very low input resistance

11. When the collector resistor in a common emitter amplifier is increased in value the voltage gain

A)Becomes erratic
B)None of the answers
C)Increases
D)Decreases

12. Which of the following describes a common collector amplifier?

A)Low input resistance
B)Low current gain
C)Low voltage gain
D)Low power gain

13. What is the main consideration in the output stage of an amplifier?

A)Current gain
B)Power output
C)Power gain
D)Voltage gain

14. An oscillator employs ​ ____ feedback.

A)Negative
B)Positive
C)Neither positive nor negative
D)Both positive and negative

15. What is the typical value of coupling capacitor Cc in RC coupling?

A)About 0.01µF
B)About 0.1µF
C)About 10µF
D)About 100 pF

16. A pulsating dc applied to power amplifiers causes

A)Hum in the circuit
B)Excessive reverse voltage
C)Burning of transistor
D)Excessive forward voltage

17. The final stage of an amplifier uses ​_____ coupling.

A)RC
B)Transformer
C)Impedance
D)Direct

18. A transistor converts

A)Ac power into dc power
B)Low resistance into high resistance
C)High resistance into low resistance
D)Dc power into ac power

19. Which frequency produces the highest noise factor?

A)1kHz
B)10kHz
C)500Hz
D)100 Hz

20. Which power amplifier has the highest collector efficiency?

A)Class B
B)Class A
C)Class AB
D)Class C

21. An LC oscillator cannot be used to produce ​______ frequencies.

A)Very high
B)High
C)Audio
D)Very low

22. The number of stages that can be directly coupled is limited because

A)Circuit becomes heavily and costly
B)Change in temperature can cause thermal instability
C)It becomes difficult to bias the circuit
D)Circuits’ resistance becomes too large

23. Class C operation can have ​_____ percent efficiency.

A)70%
B)78.5%
C)50%
D)100%

24. What oscillator circuit uses a tapped coil in the tuned circuit?

A)Colpitts
B)Hartley
C)Pierce
D)Crystal

25. What is the most stable sine-wave oscillator which uses piezo-electric quartz crystal?

A)DC restorer
B)Crystal oscillator
C)Hartley and Colpitts oscillator
D)Wien-bridge oscillator

26. Class B operation has a maximum possible frequency of ​ _____ percent.

A)2.2%
B)78.5%
C)100%
D)75%

27. In a phase shift oscillator, 180° phase-shift is obtained

A)A transformer
B)Three LC sections
C)LC tank circuit
D)Three RC sections

28. If the noise factor of an ideal amplifier is expressed in dB, then it is

A)0
B)10
C)0.1
D)1

29. Which transistor configuration offers no phase reversal at the output?

A)Common-collector
B)Common-emitter
C)Common-base
D)Both Common-base & Common-collector

30. Comparatively, power amplifier has ​ ​___​ þ.

A)Small
B)Very small
C)Large
D)Very large

31. What linear circuit compares two input signals and provides a digital level output depending on the relationship of the input signals?

A)Controller
B)Compressor
C)Switch
D)Comparator

32. A tuned amplifier is used in what application?

A)Low frequency
B)Radio frequency
C)Intermediate frequency
D)Audio frequency

33. Which of the following is NOT an oscillator requirement?

A)Amplifier
B)Feedback
C)Tank circuit
D)Attenuator

34. To obtain the frequency response curve of an amplifier ​ _____ is kept constant

A)Generator output level
B)Amplifier output
C)Generator frequency
D)Amplifier frequency

35. What is the reason why RC coupling is not used to amplify extremely low frequencies?

A)Electrical size of coupling capacitor becomes very small
B)There is considerable power loss
C)Electrical size of coupling capacitor becomes very large
D)There is a hum in the output

36. What is the purpose of the emitter capacitor?

A)To forward bias the emitter
B)To reduce noise in the amplifier
C)To stabilize emitter voltage
D)To avoid drop in gain

37. At zero signal condition, a transistor sees ​____ load.

A)ac
B)dc
C)resistive
D)both dc and ac

38. In a class A amplifier, the output signal is

A)The same as the input
B)Smaller in amplitude than the input
C)Clipped
D)Distorted

39. What type of feedback is used in Wien bridge oscillator?

A)Negative
B)Either positive or negative
C)Both positive and negative
D)Positive

40. The gain of an amplifier with feedback is known as ​_____ gain.

A)Closed loop
B)Unity
C)Resonant
D)Open loop

41. The quiescent current of a FET amplifier is

A)Id
B)id
C)IDS
D)ID

42. The stability of a regulated power supply is equivalent to

A)product of the output voltage and supply voltage
B)change of output voltage over the change in supply voltage
C)change in supply voltage over the change of output voltage
D)the difference of an output voltage to its supply voltage

43. What is the advantage of RC coupling scheme?

A)Economy
B)Good impedance matching
C)Simplicity
D)High efficiency

44. What is the maximum collector efficiency of a transformer coupled class A power amplifier?

A)30%
B)50%
C)80%
D)45%

45. When the non-linear distortion in an amplifier is D without feedback, with negative voltage feedback it will be

A)1+A ​β​/ D
B)D (1+A ​β​)
C)D (1-A ​β​)
D)D/ 1+A ​β​

46. Class C is an amplifier whose output current flows for

A)Twice the entire input cycle
B)Less than one-half the entire input cycle
C)Greater than one-half the entire input cycle
D)The entire input cycle

47. When amplifiers are cascaded

A)The gain of each amplifier is increased
B)The overall gain is increased
C)Each amplifier has to work less
D)A lower supply voltage is required

48. Which of the item below does not describe a common emitter amplifier?

A)High current gain
B)High voltage gain
C)Very high power gain
D)High input resistance

49. The bandwidth of an amplifier ​ ____ when negative feedback is applied.

A)Becomes infinite
B)Remains unchanged
C)Increases
D)Decreases

50. When CE configuration is used for an oscillator, the voltage fed back must

A)Be taken from a capacitor
B)Have a 0° phase shift
C)Be inverted by 180°
D)Taken from an inductor

51. An AF transformer is shielded to

A)Prevent electric shock
B)Protect from rusting
C)Prevent the induction due to stray magnetic fields
D)Keep the amplifier cool

52. What type of oscillator which is composed of one or more amplifying devices with some frequency determining networks introducing positive feedback at a particular frequency so that oscillation is sustained at that frequency?

A)Limiter
B)Relaxation oscillator
C)Sine wave oscillator
D)Square-wave generator

53. What class of operation has little use in general purpose amplifiers, but is used in high frequency oscillators?

A)Class A
B)Class C
C)Class AB
D)Class B

54. A tuned amplifier uses what load?

A)LC tank
B)Inductive
C)Capacitive
D)Resistive

55. An ammeter’s ideal resistance should be

A)Infinite
B)The same with the circuits resistance
C)Unity
D)Zero

56. The output power of a transistor amplifier is more than the input power due to additional power supplied by

A)Collector supply
B)Base supply
C)Emitter supply
D)Transistor

57. The number of transistor in a single stage amplifier is

A)One
B)Four
C)Three
D)Two

58. Find the voltage drop developed across a D’ Arsonval meter movement having an internal resistance of​ 1 KΩ​ and a full deflection current of 150uA.

A)150mV
B)150V
C)200mV
D)150µV

59. AC load line has a/an _____​ slope compared to that of dc load line.

A)Smaller
B)Infinite
C)Bigger
D)Zero

60. When shock-excited, a crystal will produce alternating emf longer than an LC circuit because

A)has fewer losses
B)is very rigid
C)is small-sized
D)has greater mechanical strength

61. Amplitude distortion is otherwise known as ​_____​ distortion.

A)Intermodulation
B)Phase
C)Harmonic
D)Resonant

62. What is the typical value of the emitter bypass capacitor CE in a multistage amplifier?

A)About 100pF
B)About 50µF
C)About 0.01µF
D)About 0.1µF

63. The gain of an amplifier ​_____ when negative feedback is added.

A)Reduces
B)Remains unchanged
C)Becomes infinite
D)Increases

64. In transistor amplifiers, what transformer is used for impedance matching?

A)Step down
B)Step up
C)Isolation
D)Power

65. Oscillators operate on the principle of

A)Signal feedthrough
B)Attenuation
C)Negative feedback
D)Positive feedback

66. In phase-shift oscillator, what are the frequency determining elements?

A)R and C
B)L and C
C)R and L
D)R, L and C

67. When crystal frequency increases with temperature, it has _____ temperature co- efficient.

A)Infinite
B)Positive
C)Zero
D)Negative

68. The input resistance of a common emitter amplifier is affected by

A)​Rc ​and ​re
B)​α ​and ​​re
C)​β​ and​ ​​re
D)​​Re , ​re,​​ and​ β​

69. If the capacitor from emitter to ground in a common emitter amplifier is removed, the voltage gain

A)Increases
B)None of the answers
C)Decreases
D)Becomes erratic

70. What is the time taken by the electrons or holes to pass from the emitter to the collector?

A)Transit time
B)Duty cycle
C)Transient time
D)Recombination

71. What is the gain of an amplifier with negative feedback if the feedback factor is 0.01?

A)10
B)100
C)1,000
D)500

72. Which amplifier whose output current flows for the entire cycle?

A)Class A
B)Class C
C)Class AB
D)Class B

73. Class A operation has a maximum possible efficiency of ______ percent.

A)100%
B)75%
C)50%
D)25%

74. The input impedance of an amplifier _____ when negative voltage feedback is applied.

A)Is unchanged
B)Decreases
C)Increases
D)Becomes zero

75. What is the desired input impedance of a transistor?

A)Very high
B)Low
C)Very low
D)High

76. Low efficiency of a power amplifier results in

A)Low power output
B)Less battery consumption
C)More battery consumption
D)Low forward bias

77. Transmit time is the time taken by the electrons on holes to pass from

A)Base to collector
B)Base to emitter
C)Emitter to collector
D)Collector to emitter

78. The common base (CB) amplifier has a ​______ compared to CE and CC amplifier.

A)Lower input resistance
B)Larger current gain
C)Higher input resistance
D)Larger voltage gain

79. What happens if the input capacitor of a transistor amplifier is short-circuited?

A)Signal will not reach the base
B)Transistor will be destroyed
C)Biasing conditions will change
D)Biasing will stabilize

80. Which of the following is the other name of the output stage in an amplifier?

A)Load stage
B)Audio stage
C)RF stage
D)Power stage

81. The frequency stability of the oscillator output is maximum in ​_____ oscillator.

A)LC
B)Phase-shift
C)Wien bridge
D)Crystal

82. Transformer coupling is generally employed when load resistance is

A)Zero
B)Large
C)Very large
D)Small

83. What is the point of intersection of dc and ac load lines called?

A)Cut off point
B)Saturation point
C)Breakdown
D)Operating point

84. When negative current feedback is applied to an amplifier, its output impedance

A)remains unchanged
B)decreases
C)increases
D)becomes zero

85. Generally tuned amplifiers are operated in

A)Class A
B)Class C
C)Class B
D)Class AB

86. What is the purpose of capacitors in a transistor amplifier?

A)To provide biasing
B)To couple or bypass ac component
C)To cool the transistor
D)To protect the transistor

87. For constant- K high-pass filter cut-off frequency (in Hz) is given by

A)1/​(2π​√LC)
B)1/(4π​√LC)
C)​π​/√LC
D)1 /​(π​√LC)

88. Consider a zener diode with a slope resistance of​ 10Ω ​in series with a​ 90Ω ​resistor fed from a dc supply containing a ripple voltage of 20mV peak-to-peak.​

Compute for the ripple voltage in load

A)1 mV p-p
B)2 mV p-p
C)6mV p-p
D)1 V p-p

89. The ac variations at the output side of power supply circuits are called ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ .

A)Pulses
B)Ripples
C)Filters
D)Waves

90. Transformer coupling can be used in _____ amplifiers

A)Either power or voltage
B)Only power
C)Neither power nor voltage
D)Only voltage

91. Transformer coupling is used for _____ amplification.

A)Signal
B)Power
C)Voltage
D)Current

92. To sustain oscillations, the power gain of the amplifier may be

A)Infinite
B)Any value form 0.5 upward
C)Between 0.1 and 0.5
D)Equal to or greater than 1

93. The input capacitor in an amplifier is called ​_____​ capacitor.

A)Stray
B)Electrolytic
C)Bypass
D)Coupling

94. Class C operation is preferred in oscillators because it

A)Gives larger outputs
B)Produces square waves
C)Is more efficient
D)Increases stability

95. In a multistage amplifier, if the stages have R and C component only, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ operation is apparent.

A)Class B
B)Class C
C)Class AB
D)Class A

96. Which operation gives the maximum distortion?

A)Class B
B)Class A
C)Class AB
D)Class C

97. The total decibel voltage gain of two cascaded voltage amplifier where individual voltage gains are 10 and 100 is

A)1000
B)20
C)60
D)800

98. For a constant output frequency, the simplest sinusoidal oscillator is the ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ .

A)Phase-shift circuit
B)Colpitts circuits
C)Crystal oscillator
D)Hartley circuit

99. If you move towards an oscillating circuit, its frequency changes because of

A)Movement of the body
B)Stray capacitance
C)Noise of foot
D)Hand capacitance

100. The _____ of a common collector configuration is unity

A)Current gain
B)Input impedance
C)Power gain
D)Voltage gain

101. What type of coupling is generally used in power amplifiers?

A)Transformer
B)RC
C)Direct
D)Inductive

102. In a Colpitt’s oscillator, feedback is obtained

A)By a tickler coil
B)From the center of split inductors
C)From the center of split capacitors
D)By magnetic induction

103. What is the disadvantage of impedance matching?

A)It gives distorted output
B)It requires a transformer
C)It is expensive
D)It gives low power output

104. buffer amplifier is used for

A)Minimum loading and maximum mismatch
B)Minimum loading and minimum mismatch
C)Maximum loading and maximum mismatch
D)Maximum loading and minimum mismatch

105. In order to have more voltage gain from a transformer amplifier the transistor used should have

A)Thin base
B)Thin emitter
C)Wide emitter
D)Thin collector

106. The output transformer used in a power amplifier is a/an _____ transformer

A)Isolation
B)Step-down
C)Step-up
D)1:1 ratio

107. Feedback circuit usually employs ​​______ network

A)Inductive
B)Resistive
C)Capacitive
D)Active

108. An ideal differential amplifiers common mode rejection ratio is

A)Zero
B)Infinite
C)Unity
D)Undetermined

109. A type of oscillator wherein the frequency is determined by the charge and discharge of resistor capacitor networks used in conjunction with amplifiers or similar devices.

A)Sine wave oscillator
B)Relaxation oscillator
C)Beta generating circuit
D)Simply an oscillator

110. When negative voltage feedback is applied to an amplifier, its output impedance

A)Increases
B)Becomes zero
C)Decreases
D)Remains unchanged

111. Hartley oscillator is commonly used in which of the following?

A)TV receivers
B)Radio transmitters
C)Radio receivers
D)CATV

112. Which is a fixed-frequency oscillator

A)Crystal oscillator
B)Phase-shift oscillator
C)Colpitt’s oscillator
D)Hartley oscillator

113. RC coupling is used for ​ ______ amplification.

A)Power
B)Current
C)Voltage
D)Signal

114. A complementary-symmetry amplifier has

A)One PNP and one NPN transistor
B)Two PNP and two NPN transistors
C)Two PNP transistors
D)Two NPN transistors

115. The term 1+ A þ in the expression for gain with negative feedback is known as

A)Sacrifice factor
B)Gain factor
C)Feedback factor
D)Quality factor

116. In a common emitter amplifier, the capacitor from emitter to ground is called the

A)Tuning capacitor
B)Coupling capacitor
C)Decoupling capacitor
D)Bypass capacitor

117. What class of operation is used either where the signal needs to be cut in half, such as in pulse detector or noise detectors or where push-pull operation of two stages is required?

A)Class AB
B)Class B
C)Class A
D)Class C

118. What is the ideal maximum voltage gain of a common collector amplifier?

A)Zero
B)Infinite
C)Indeterminate
D)Unity

119. The capacitors are considered ______ in the ac equivalent circuit of a transistor amplifier.

A)Partially open
B)Open
C)Short
D)Partially short

120. Transformer coupling introduces what type of distortion?

A)Frequency
B)Intermodulation
C)Amplitude
D)Phase

121. What coupling provides maximum voltage gain?

A)Direct
B)RC
C)Transformer
D)Resistor

122. Which of the items below is not a description of the two-stage amplifier?

A)The input resistance is equal to the input resistance of the first stage unless feedback is applied
B)Its output resistance is equal to the output resistance of the final stage unless feedback is applied
C)The output resistance is equal to the output resistance of the first stage unless feedback is applied.
D)Its noise level is equal to the accumulated noise of the two stages, either by multiplying the noise voltage amplitudes together or by adding the noise decibel levels together

123. Increasing the overall Beta is an advantage of

A)Crystal oscillator
B)Darlington pair
C)Clap oscillator
D)CE amplifier

124. What is the purpose of dc conditions in a transistor?

A)To reverse bias the emitter
B)To set up operating point
C)To forward bias the emitter
D)To turn on the transistor

125. Which of the following is provided by a CB transistor amplifier?

A)Voltage gain
B)Gain stability
C)Power gain
D)Current gain

126. What is the phase difference between the output and the input voltage of a CE amplifier?

A)90°
B)180°
C)
D)270°

127. For highest power gain, what configuration is used?

A)CB
B)CE
C)CS
D)CC

128. An oscillator oscillates due to

A)Both positive and negative feedback
B)Negative feedback
C)Positive feedback
D)Neither positive nor negative feedback

129. What oscillator is used on order to produce frequencies in the microwave region?

A)Crystal
B)Hartley
C)Klystron
D)Wien bridge

130. What is the basic purpose of applying negative feedback to an amplifier?

A)To increase input signal
B)To increase gain
C)To reduce distortion
D)To keep the temperature within limits

131. Determine the attenuation in dB for a T-pad for which R1=R2=​ 40Ω ​and R3=​ 36Ω​ .​

The pad connects a​ 50Ω ​generator to a​ 50Ω​ load.

A)83.93 dB
B)11.93 dB
C)10.83 dB
D)9.83 dB

132. What is the ratio of output to the input impedance of a CE amplifier?

A)Approximately 1
B)Moderate
C)Very high
D)Very low

133. Which is used to establish a fixed level of current or voltage in a transistor?

A)Loading
B)Load line
C)Biasing
D)Coupling

134. What class of operation is used for general amplification where no distortion can be tolerated?

A)Class AB
B)Class A
C)Class C
D)Class B

135. The signal generator generally used in laboratories is​ _____ oscillator

A)Wien-bridge
B)Hartley
C)Phase-shift
D)Crystal

136. What is the axis that connects the corners of a crystal?

A)Mechanical
B)X
C)Y
D)Z

137. When the gain is 20 without feedback and 12 with negative feedback, feedback factor is

A)5/3
B)1/5
C)0.033
D)3/5

138. What circuit increases the peak–to–peak voltage, current or power of a signal?

A)Amplifier
B)Power supply
C)Attenuator
D)Filter

139. A multistage amplifier uses at least how many transistors?

A)Four
B)One
C)Three
D)Two

140. Emitter follower employs _____ negative feedback.

A)100%
B)50%
C)25%
D)75%

141. What is the purpose of RC or transformer coupling?

A)To increase thermal stability
B)To block ac
C)To block dc
D)To separate bias of one stage from another

142. What is the most important characteristic of a common collector amplifier?

A)High input voltage
B)Its being an amplifier circuit
C)High input resistance
D)High output resistance

143. The input impedance of which amplifier depends strongly on load resistance?

A)CB
B)CC
C)CE
D)CD

144. What application where one would most likely find a crystal oscillator?

A)AF generator
B)Oscilloscope
C)Radio receiver
D)Radio transmitter

145. The frequency response of the combined amplifier can be compared with

A)A positive filter
B)A negative feedback amplifier
C)An OR gate
D)An AND gate

146. The simplest variable frequency sinusoidal oscillator is the

A)Armstrong circuit
B)Complicated Colpitts circuit
C)Crystal circuit
D)Phase shift circuit

147. A common-emitter circuit is also called ​_____ circuit.

A)Emitter follower
B)Grounded base
C)Grounded collector
D)Grounded emitter

148. Logic analyzer is used to

A)To analyze the logic operation of the system
B)To sample and display systems signal
C)Verify the logic operation of the gates in a circuit
D)To display the fall time

149. The driver transformer has center-tapped secondary to provide

A)Forward bias to transistors of push-pull circuit
B)Two signals in phase with each other
C)Two signals 180 degrees out of phase to transistors of push-pull circuit
D)Impedance matching

150. In the initial stages of a multistage amplifier, ​ ______ coupling is used.

A)RC
B)Transformer
C)Impedance
D)Link

151. Class C amplifiers are used as

A)IF amplifiers
B)RF amplifiers
C)AF amplifiers
D)Small signal amplifiers

152. The operating frequency of a Wien-bridge oscillator is given by

A)1/​(4πLC)​
B)1/​29RC​
C)1/(​2π​LC)
D)1/(​2πRC​)

153. A two-transistor class B power amplifier is commonly called

A)Dual amplifier
B)Differential amplifier
C)Symmetrical amplifier
D)Push-pull amplifier

154. What is the operating point in the characteristic curve called?

A)Saturation point
B)Biasing point
C)Quiescent point
D)Load point

155. Power amplifiers generally use transformer coupling because transformer coupling provides

A)Cooling of the circuit
B)Good frequency response
C)Distortionless output
D)Impedance matching

156. The ear is not sensitive to _____​ distortion.

A)Phase
B)Amplitude
C)Frequency
D)Harmonic

157. A class A power amplifier uses ​_____ transistor(s).

A)Two
B)One
C)Four
D)Three

158. An emitter follower is equivalent to

A)Common base amplifier
B)Hybrid connection
C)Common emitter amplifier
D)Common collector amplifier

159. Feedback factor is always

A)Equal to 1
B)Zero
C)Less than 1
D)More than 1

160. If gain without feedback and feedback factor are A and þ respectively, then gain with negative feedback is given by

A)(1+A ​β​) A
B)1+A ​β​ / A
C)A/ 1-A ​β​
D)A/ 1+ A ​β​

161. The voltage gain over mid- frequency range in an RC coupled amplifier

A)Changes instantly with frequency
B)Is independent of the coupling
C)Is constant
D)Is maximum

162. The bandwidth of a single stage amplifier is ______ that of multistage amplifier.

A)Less than
B)More than
C)Equal to
D)Independent

163. In an LC oscillator, if the value of L is increased four times, then the frequency of oscillation is

A)Increased 4 times
B)Increased 2 times
C)Decreased 2 times
D)Decreased 4 times

164. A feedback circuit is _____ frequency

A)Independent of
B)Relatively dependent on
C)Moderately dependent on
D)Strongly dependent on

165. Power amplifiers handle ​_____​ signals.

A)Very small
B)Very large
C)Large
D)Small

166. Which of the following amplifier is considered linear?

A)Either Class A or B
B)Class C
C)Class A
D)Class B

167. Which configuration has the lowest current gain?

A)Common-collector
B)Emitter follower
C)Common-base
D)Common-emitter

168. The efficiency of class AB operation has a maximum of between ​_____​ percent.

A)50 to 78.5%
B)90 to 100%
C)40.5 to 60%
D)60 to 80%

169. An open fuse circuit has a resistance equal to

A)Zero
B)Infinity
C)Unity
D)At least​ 100Ω ​at standard

170. Series current negative feedback occurs when the feedback voltage is proportional to the output

A)Current
B)Power
C)Voltage
D)Impedance

171. Which of the following is not a FET amplifier configuration?

A)Common source amplifier
B)Common gate amplifier
C)Common drain amplifier
D)Common base amplifier

172. What capacitors are used in transistor amplifiers?

A)Electrolytic
B)Paper
C)Mylar
D)Mica

173. In an LC circuit, when the capacitor energy is maximum, the inductor energy is

A)Zero
B)Half-way between maximum and minimum
C)Maximum
D)Minimum

174. When the gain versus frequency curve of a transistor amplifier is not flat, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ distortion is present.

A)Frequency
B)Intermodulation
C)Amplitude
D)Phase

175. Transformer coupling provides high gain because

A)Impedance matching can be achieved
B)Transformer is very efficient
C)Transformer steps up the current
D)Transformer steps up the voltage

176. Which of the following is considered an amplifier figure of merit?

A)Gain-bandwidth product
B)Alpha(​α​)
C)Beta(​β​)
D)Temperature

177. If an amplifier has a power gain of 100, then its dB gain is

A)10
B)20
C)40
D)100

178. An oscillator produces ______ oscillations.

A)Sinusoidal
B)Damped
C)Undamped
D)Modulated

179. The largest theoretical voltage gain obtained with a common collector amplifier is

A)Infinite
B)Unity
C)10
D)100

180. Given three amplifiers with a gain of 10 and are connected in cascade. How much is the overall gain?

A)10,000
B)20
C)24
D)30

181. In practice, what is normally varied in order to change the frequency of oscillation?

A)Resistance
B)Impedance
C)Inductance
D)Capacitance

182. When a transistor is cut off

A)Maximum voltage appears across transistor
B)Maximum current flows
C)Minimum current flows
D)Maximum voltage appears across load

183. The operating point is generally located at ​ _____ of dc load line in class A operation

A)End point
B)Saturation point
C)Cut off point
D)The middle

184. The output signal of a common-collector amplifier is always

A)Larger than the input signal
B)In phase with the input signal
C)Out of phase with the input signal
D)Exactly equal to the input signal

185. To obtain good gain stability in a negative feedback amplifier, AB is

A)Zero
B)Equal to 1
C)Less than 1
D)Very much greater than 1

186. Which of the following amplifier below is a choice when higher power gain is a requirement?

A)Hybrid connection
B)Common emitter
C)Common collector
D)Common base

187. Parasitic oscillations are caused by

A)Push-pull operation
B)Poor interstage coupling
C)Output negative feedback
D)Transistor interelectrode capacitance

188. The impedance of a load must match the impedance of the amplifier so that

A)The efficiency can be maintained at low level
B)The signal-to-noise ratio is maximized
C)Maximum power is transferred to the load
D)Minimum power is transferred to the load

189. Which coupling has the best frequency response?

A)Transistor
B)RC
C)Direct
D)Transformer

190. What is the most important consideration in power amplifiers?

A)Amplifier distortion
B)To keep the transformer cool
C)Collector efficiency
D)Biasing the circuit

191. The push-pull circuit must use _____ operation.

A)Class A
B)Class AB
C)Class C
D)Class B

192. What is the approximate gain of an amplifier with negative feedback?

A)The reciprocal of feedback factor plus one
B)The feedback factor plus one
C)The feedback factor
D)The reciprocal of feedback factor

193. What is the purpose of the bypass capacitor in a common-emitter amplifier?

A)It provides ac grounding
B)It decreases voltage gain
C)No effect in the circuit
D)It increases voltage gain

194. Cascaded amplifiers total decibel gain is equal to

A)The difference of the individual gains
B)The sum of the individual gains
C)The quotient of the individual gains
D)The product of the individual gains

195. What is the typical Q of a crystal?

A)More than 10,000
B)50
C)100
D)1000

196. A transistor amplifier has high output impedance because

A)Collector is wider than emitter or base
B)Emitter is heavily doped
C)Collector has reverse bias
D)Emitter has forward bias

197. The _____ the voltage regulation, the better the operation of the voltage supply circuit.

A)Smaller
B)Moderate
C)Bigger
D)Biggest

198. The input impedance of an amplifier _____​ when negative current feedback is applied.

A)Becomes zero
B)Increases
C)Remains unchanged
D)Decreases

199. The crystal oscillator frequency is very stable due to ​____ of the crystal.

A)High Q
B)Low Q
C)Rigidity
D)Ductility

200. The three amplifiers are connected in a multistage arrangement each with a voltage gain of 30.​

Compute for the overall voltage gain.

A)30
B)27,000
C)10
D)90

201. A type of filter which is having a single continuous transmission band with neither the upper nor the lower cut-off frequencies being zero or infinite is called

A)Band pass filter
B)Band stop filter
C)Low pass filter
D)High pass filter

202. The maximum collector efficiency of class B operation is

A)5%
B)90%
C)60.5%
D)78.5

203. An electronic transfer from one stage to the next is termed as ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

A)Mixing
B)Doping
C)Connecting
D)Coupling

204. What is the piezoelectric effect in a crystal?

A)Voltage is developed because of mechanical stress
B)Change of frequency because of temperature
C)Change in resistance because of temperature
D)Current is developed due to force applied

205. To amplify dc signals, multistage amplifier uses what coupling?

A)Resistor
B)Transformer
C)Direct
D)RC

206. The coupling capacitor Cc must be large enough to ____ in an RC coupling scheme.

A)Prevent attenuation of low frequency
B)Pass dc between the stages
C)Dissipate high power
D)Prevent attenuation of high frequency

207. What represents common-emitter small signal input resistance?

A)​hoe​
B)​​hfe​
C)​​hib​
D)​​hie​

208. The value of collector load resistance in a transistor amplifier is ​ _____ ​ the output impedance of the transistor.

A)Equal to
B)Not related
C)Less than
D)More than

209. What is the most costly coupling?

A)Direct
B)Transformer
C)Inductive
D)RC coupling

210. The ratio output rms power in watts to the input dc power in watts in the different amplifier class is called ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ .

A)Amplification factor
B)Efficiency
C)Gain
D)Phase power

211. The capacitors are considered ​_____ in the dc equivalent circuit of a transistor amplifier.

A)Partially short
B)Short
C)Partially open
D)Open

212. Negative feedback is employed in

A)Amplifiers
B)Rectifiers
C)Receivers
D)Oscillators

213. The current in any branch of a transistor amplifier that is operating is

A)dc only
B)ac only
C)the difference of ac and dc
D)the sum of ac and dc

214. What is the device in a transistor oscillator?

A)Feedback circuit
B)Biasing circuit
C)Transistor
D)LC tank circuit

215. When the output of an amplifier is 10V and 100mV from the output is fed back to the input, feedback factor is

A)0.15
B)10
C)0.1
D)0.01

216. A dc voltage supply provides 60V when the output is unloaded.​

When connected to a load the output drops to 56V.​

Calculate the value of the voltage regulation.

A)5%
B)12%
C)8.1%
D)7.1%

217. One of the items below is a characteristic of cascaded amplifiers?

A)Doubles transconductance
B)Increased overall gain
C)Increased overall amplification ratio
D)Total gain is lessen

218. In an LC oscillator, the frequency of oscillations is given by

A)​2π​/√LC
B)√LC/​2π​
C)​4π​/√LC
D)1/(​2π​√LC)

219. Calculate the ripples of the filter output if a dc and ac voltmeter is used and measures the output signal from a filter circuit of 25​ VDC​ and 1.5​ Vrms​

A)5%
B)10%
C)6%
D)50%

220. What piece of equipment in an oscilloscope is used to indicate pulse condition in a digital logic circuit?

A)Connector
B)Probe
C)Test probe
D)Logic probe

221. The frequency of oscillation is ​_____ L and C in an LC oscillator.

A)Proportional to square of
B)Inversely proportional to square root of
C)Independent of the values of
D)Directly proportional to

222. An important limitation of crystal oscillator is

A)Less availability of quartz crystal
B)Its high Q
C)Its high output
D)Its low output

223. Why is it that the size of a power transistor is made considerably large?

A)To facilitate connections
B)To simply construction
C)To dissipate more heat
D)To provide easy handling

224. Why is transformer coupling provides high frequency?

A)AC resistance is high
B)DC resistance is low
C)Collector voltage is stepped up
D)Collector voltage is stepped down

225. What is a non-linear type of amplifier?

A)Class A
B)Class AB
C)Class C
D)Class B

226. An instrument use to measure ones location in terms of coordinates

A)ILS
B)FANS
C)GPS
D)GSM

227. What is usually employed at the output stage of an amplifier?

A)Pre-amplifier
B)Class A power amplifier
C)Push-pull amplifier
D)Differential amplifier

228. An amplifier configuration where the input signal is led to the emitter terminal and the output from the collector terminal is called

A)Common base
B)Clipper
C)Common collector
D)Common emitter

229. CC configuration is used for impedance matching because its

A)Output impedance is zero
B)Input impedance is very high
C)Output impedance is very low
D)Input impedance is very low

230. The output signal of CE amplifier is always

A)In phase with the input signal
B)Out of phase with the input signal
C)Equal to the input signal
D)Larger than the input signal

231. The frequency of the ripple voltage at the output of a full-wave rectifier at 60 cycles.

A)120 cycles
B)240 cycles
C)480 cycles
D)60 cycles

232. When a FET with a lower transconductance is substituted into a FET amplifier circuit, what happens?

A)The circuit disamplifies
B)The current gain does not change
C)The input resistance decreases
D)The voltage gain decreases

233. In a phase-shift oscillator, ​______ RC sections are generally used.

A)Five
B)Two
C)Three
D)Four

234. The current gain of an emitter follower is

A)Zero
B)Greater than 1
C)Equal to 1
D)Less than 1

235. What class of operation is used where a portion of a signal only is required, such as the synchronizing pulse separator of a television receiver?

A)Class B
B)Class C
C)Class A
D)Class AB

236. The approximate operating frequency of a phase shift oscillator is given by

A)1/(​2π RC​)
B)1/​(29 RC​)
C)1/(​2π​√LC)​
D)1/(​2π​RC√6)

237. A class A power amplifier is otherwise known as

A)Differential amplifier
B)Symmetrical amplifier
C)Single ended amplifier
D)Darlington amplifier

238. The operating point in a transistor amplifier moves along ​_____​ when an ac signal is applied

A)both dc and ac load lines
B)cut-off
C)ac load line
D)dc load line

239. When the collector supply is 5V, then collector cut off voltage under dc condition is

A)5V
B)2.5V
C)20V
D)10V

240. When a transistor amplifier feeds a load of low resistance, its voltage gain will be

A)Low
B)Moderate
C)Very high
D)High

241. An oscillator converts

A)electrical power into mechanical power
B)mechanical power into ac power
C)ac power into dc power
D)dc power into ac power

242. What is the maximum collector efficiency of a resistance loaded class A power amplifier?

A)78.5%
B)30%
C)50%
D)25%

243. The power input to a power amplifier is ______​ quantity.

A)ac
B)sinusoidal
C)Pulsating dc
D)dc

244. The frequency response of transformer coupling is

A)Poor
B)Good
C)Very good
D)Excellent

245. The basic concept of the electric wave filter was originated by

A)Foster
B)Norton
C)Campbell and Wagner
D)Bode and Darlington

246. Emitter follower is used for

A)Current gain
B)Voltage gain
C)Power gain
D)Impedance matching

247. If Av is 50 Ai is 200, what is the power gain of a common emitter amplifier?

A)100,000
B)1,000
C)10,000
D)100

248. The driver stage usually employs ​_____​ amplifier.

A)Push-pull
B)Class AB
C)Class C
D)Class A power

249. Quartz crystal is most commonly used in crystal oscillators because

A)It is quite inexpensive
B)It is very rugged
C)It is easily available
D)It has superior electrical properties

250. The collector current in an common base configuration is equal to

A)Alpha times base current plus leakage current
B)Beta times emitter current plus leakage current
C)Beta times collector current plus leakage current
D)Alpha times emitter current plus leakage current

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