Bipolar Junction Transistor MCQs

Question 1

Arrow head on a transistor symbol indicates

Accepted Answer

Direction of hole current in emitter

Answer

Direction of electron current in emitter

Answer

Diffusion current in emitter

Answer

Drift current in emitter

Question 2

Conventional biasing of a bipolar transistor has

Accepted Answer

EB forward biased and CB reverse biased

Answer

EB forward biased and CB forward biased

Answer

EB reversed biased and CB forwaqrd biased

Answer

EB reversed biased and CB reverse biased

Question 3

Which of the following number specification refers to FET with one gate

Accepted Answer

3N

Answer

2N

Answer

3Y

Answer

3X

Question 4

A diac is a semi-conductor device which acts as a

Accepted Answer

2 terminal bidirectional switch

Answer

2 terminal unidirectional switch

Answer

3 terminal bidirectional switch

Answer

4 terminal multi-directional switch

Question 5

Which of the following is necessary for transistor action?

Accepted Answer

The base region must be very narrow

Answer

The base region must be very wide

Answer

The base region must be made of some insulating material

Answer

The collector region must be heavily doped

Question 6

In a transistor, current 1030 flows when

Accepted Answer

some dc voltage is applied in the reverse direction to the collector junction with the emitter open circuited

Answer

some dc voltage is applied in the reverse direction to the emitter junction with the collector open circuited

Answer

some dc voltage is applied in the forward direction to the collector junction with the emitter open circuited

Answer

some dc voltage is applied in the forward direction to the emitter junction with the collector open-circuited.

Question 7

The current Icao

Accepted Answer

increases with increase in temperature

Answer

is normally greater for silicon transistors than germanium transistors

Answer

mainly depends on the emitter base junction bias

Answer

depends largely on the emitter doping

Question 8

Thermal run away of a transistor occurs when

Accepted Answer

there is excessive leakage current due temperature rise

Answer

heat dissipation from transistor is excessive

Answer

transistor joints melt due to high temperature

Answer

none of the above

Question 9

For a transistor the normal collector voltage is 12 V. If actually it is found to be 28+ V, the trouble could be

Accepted Answer

RE is open

Answer

RL is open

Answer

CE is shorted

Answer

CE is open