HARD

Earn 100

Draw the diagram for transistor being used as a switch.

Important Questions on Semiconductor Devices

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

In a common-emitter transistor amplifier, the audio signal voltage across the collector is

3 V.

The resistance of collector is

3 kΩ

. If current gain is

100

and the base resistance is

2 kΩ

, the voltage and power gain of the amplifier is

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

In a common emitter amplifier circuit using an

n - p - n

transistor, the phase difference between the input and the output voltages will be:

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

The current gain of a common emitter amplifier is

69

. If the emitter current is

7.0 mA

, collector current is :

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

An unknown transistor needs to be identified as a

n p n

p n p

type. A multimeter, with +ve and -ve terminals, is used to measure resistance between different terminals of transistor. If terminal 2 is the base of the transistor then which of the following is correct for a

p n p

transistor?

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

A NPN transistor is connected in common emitter configuration in a given amplifier. A load resistance of

800 Ω

is connected in the collector circuit and the voltage drop across it is

0 .8

V

. If the current amplification factor is

0.96

and the input resistance of the circuit is

192 Ω

, the voltage gain and the power gain of the amplifier will respectively be:

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

For a common emitter configuration, if

α

and

β

have their usual meanings, the correct relationship between

α

and

β

is:

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

For a transistor,

α_{d c}

and

β_{d c}

are the current ratios, then the value of

\frac{β_{d c} - α_{d c}}{α_{d c} \cdot β_{d c}}

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

NPN

transistor operates as a common emitter amplifier, with a power gain of

60 d B

. The input circuit resistance is

100 Ω

and the output load resistance is

10 k Ω

. The common emitter current gain

β

is:

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

In the figure, given that $V_{B B}$ supply can vary from $0$ to $5.0 V, V_{C C} = 5 V, β_{d c} = 200,$ $R_{B} = 100 kΩ,$ $R_{C} = 1 kΩ$ and $V_{B E} = 1.0 V.$ The minimum base current and the input voltage at which the transistor will go to saturation, will be, respectively:

Question Image

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

The input signal is given to a CE amplifier having a voltage gain of

150

V_{i} = 2 \cos (15 t + \frac{π}{3})

. The corresponding output signal will be:

HARD

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

A realistic graph depicting the variation of the reciprocal of input resistance in an input characteristics measurement in a common emitter transistor configuration is :

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

For a transistor to act as a switch, it must be operated in

EASY

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

The ratio (R) of output resistance

r_{0},

and the input resistance

r_{i}

in measurements of input and output characteristics of a transistor is typically in the range :

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

An n-p-n transistor has three leads A, B and C. Connecting B and C by moist fingers, A to the positive lead of an ammeter, and C to the negative lead of the ammeter, one finds large deflection. Then, A, B and C refer respectively to :

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

A common emitter amplifier circuit, built using an NPN transistor, is shown in the figure. Its dc current gain is

250

R_{C} = 1 kΩ

and

V_{C C} = 10 V

. The minimum base current for

V_{C E}

to reach saturation is

Question Image

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Transistor as a Switch

The transfer characteristic curve of a transistor, having input and output resistance $100 Ω$ and $100 k Ω$ respectively, is shown in the figure. The voltage and power gain, are respectively:
Question Image