The barrier potential of a silicon diode is approximately, ______.

(a)

0.7 V

(b)

0.3 V

(c)

2.0 V

(d)

2.2 V

If a small amount of antimony (Sb) is added to germanium crystal,______.

(a)

it becomes a p-type semiconductor

(b)

the antimony becomes an acceptor atom

(c)

there will be more free electrons than hole in the semiconductor

(d)

its resistance is increased

A forward biased diode is treated as ________________.

(a)

An open switch with infinite resistance

(b)

A closed switch with a voltage drop of 0V

(c)

A closed switch in series with a battery voltage of 0.7V

(d)

A closed switch in series with a small resistance and a battery

If a positive half-wave rectified voltage is fed to a load resistor, for which part of a cycle there will be current flow through the load?

(a)

0⁰–90⁰

(b)

90⁰–180⁰

(c)

0⁰–180⁰

(d)

0⁰–360⁰

The zener diode is primarily used as ______.

(a)

Rectifier

(b)

Amplifier

(c)

Oscillator

(d)

Voltage regulator

The principle based on which a solar cell operates is______.

(a)

Diffusion

(b)

Recombination

(c)

Photovoltaic action

(d)

Carrier flow

The light emitted in an LED is due to ______.

(a)

Recombination of charge carriers

(b)

Reflection of light due to lens action

(c)

Amplification of light falling at the junction

(d)

Large current capacity

When a transistor is fully switched on, it is said to be _________________.

(a)

Shorted

(b)

Saturated

(c)

Cut-off

(d)

Open

The specific characteristic of a common emitter amplifier is _______________.

(a)

High input resistance

(b)

Low power gain

(c)

Signal phase reversal

(d)

Low current gain

To obtain sustained oscillation in an oscillator,______.

(a)

Feedback should be positive

(b)

Feedback factor must be unity

(c)

Phase shift must be 0 or 2π

(d)

All the above

If the input to the NOT gate is A = 1011, its output is ______.

(a)

0100

(b)

1000

(c)

1100

(d)

0011

The electrical series circuit in digital form is

(a)

AND

(b)

OR

(c)

NOR

(d)

NAND

Which one of the following represents forward bias diode?

(a)

(b)

(c)

(d)

The given electrical network is equivalent to ______.

(a)

AND gate

(b)

OR gate

(c)

NOR gate

(d)

NOT gate

The output of the following circuit is 1 when the input ABC is______.

(a)

101

(b)

100

(c)

110

(d)

010

The output transducer of the communication system converts the radio signal into ________.

(a)

Sound

(b)

Mechanical energy

(c)

Kinetic energy

(d)

None of the above

The signal is aff ected by noise in a communication system _____________.

(a)

At the transmitter

(b)

At the modulator

(c)

In the channel

(d)

At the receiver

The variation of frequency of carrier wave with respect to the amplitude of the modulating signal is called ______.

(a)

Amplitude modulation

(b)

Frequency modulation

(c)

Phase modulation

(d)

Pulse width modulation

The internationally accepted frequency deviation for the purpose of FM broadcasts ____________.

(a)

75 kHz

(b)

68 kHz

(c)

80 kHz

(d)

70 kHz

The frequency range of 3 MHz to 30 MHz is used for ______.

(a)

Ground wave propagation

(b)

Space wave propagation

(c)

Sky wave propagation

(d)

Satellite communication