Electronic Devices & Circuits Quiz – Set 1

Calculate the stability factor and change in IC from 25°C to 100°C for, β = 50, R_B/ R_E = 250, ΔIC0 = 19.9 nA for emitter bias configuration.

In which region of a CE bipolar transistor is collector current almost constant?

Assertion (A): The conductivity of p type semiconductor is higher than that of intrinsic semiconductor.
Reason (R): The addition of donor impurity creates additional energy levels below conduction band.

As compared to an ordinary semiconductor diode, a Schottky diode

In p-n-p transistor the current I_E has two components viz. I_EP due to injection of holes from p-region to n-region and I_E due to injection of electrons from n-region to p-region. Then

The types of carriers in a semiconductor are

A zener diode is used in

In the circuit of figure the function of resistor R and diode D are

At very high temperatures the extrinsic semi conductors become intrinsic because

Which of the following is true as regards photo emission?

A transistor has two p-n junctions. The batteries should be connected such that

In an n-p-n transistor, the majority carriers in the base are

The power dissipation in a transistor is the product of

Assertion (A): A p-n junction has high resistance in reverse direction.
Reason (R): When a reverse bias is applied to p-n junction, the width of depletion layer increases.

Crossover distortion behaviour is characteristic of

The normal operation of JFET is

In an n channel JFET, the gate is

The most commonly used semiconductor material is

The number of doped regions in PIN diode is

Assertion (A): When a high reverse voltage is applied to a p-n junction the diode breaks down.
Reason (R): High reverse voltage causes Avalanche effect.

When a voltage is applied to a semiconductor crystal then the free electrons will flow.

Recombination produces new electron-hole pairs

In a bipolar transistor which current is largest

In an n-p-n transistor biased for operation in forward active region

In a p type material the Fermi level is 0.3 eV above valence band. The concentration of acceptor atoms is increased. The new position of Fermi level is likely to be

If α_ac for transistor is 0.98 then β_ac is equal to

An increase in temperature increases the width of depletion layer.

Assertion (A): The reverse saturation current in a semiconductor diode is 4nA at 20°C and 32 nA at 50°C.
Reason (R): The reverse saturation current in a semiconductor diode doubles for every 10°C rise in temperature.

In a zener diode

The amount of photoelectric emission current depends on

An LED has a rating of 2 V and 10 mA. It is used along with 6V battery. The range of series resistance is

At room temperature the current in an intrinsic semiconductor is due to

In a bipolar transistor the barrier potential

As compared to an ordinary semiconductor diode, a Schottky diode

A particular green LED emits light of wavelength 5490, Å, the energy bandgap of the semiconductor material used there is .. h = 6.6 x 10^-34 J sec.

A transistor has a current gain of 0.99 in the CB mode. Its current gain in the CC mode is

Secondary emission is always decremental.

In which of these is reverse recovery time nearly zero?

Work function is the maximum energy required by the fastest electron at 0 K to escape from the metal surface.

The v-i characteristics of a FET is shown in figure. In which region is the device biased for small signal amplification

A periodic voltage has following value for equal time intervals changing suddenly from one value to next... 0, 5, 10, 20, 50, 60, 50, 20, 10, 5, 0, -5, -10 etc. Then rms value of the waveform is

Ferrite have

A potential of 7 V is applied to a silicon diode. A resistance of 1 K ohm is also in series with the diode. The current is

A silicon (PN) junction at a temperature of 20°C has a reverse saturation current of 10 pico Ampere. The reverse saturation current at 40°C for the same bias is approximately.

An amplifier without feedback has a voltage gain of 50, input resistance of 1 kΩ and output resistance of 2.5 kΩ. The input resistance of the current shunt -ve feedback amplifier using the above amplifier with a feedback factor of 0.2 is

The word enhancement mode is associated with

The minority carrier life time and diffusion constant in a semiconductor material are respectively 100 microsecond and 100 cm²/sec. The diffusion length is

A p-n junction diode has

Work function of oxide coated cathode is much lower than that of tungsten cathode.

In a degenerate n type semiconductor material, the Fermi level,