Bipolar Junction Transistor (BJT) MCQ [Questions with Answers]

The Bipolar Junction Transistor (BJT) is a basic type of transistor. The BJT is a three-terminal device: Base, Collector, and Emitter. The term bipolar refers to the use of both holes and electronics as current carriers.

Given below are the BJT MCQ Questions with answers for Electrical Engineering Exams, Job tests, and interviews.

Three regions of BJT are

Three regions of BJT are:

  1. Emitter, Collector, and Gate
  2. Emitter, Base and Collector
  3. Emitter, Gate, and Source
  4. Source, Drain, and Collector

Correct answer: 2. Emitter, Base and Collector


The region which is lightly doped in BJT is

The region which is lightly doped in BJT is:

  1. Base
  2. Collector
  3. Emitter
  4. Any of above

Correct answer: 1. Base


The region of BJT which is heavily doped

The region which is heavily doped:

  1. Base
  2. Collector
  3. Emitter
  4. Any of above

Correct answer: 3. Emitter


In a transistor IC = Ic mA and IE = Ie mA. The value of β is

In a transistor IC = Ic mA and IE = Ie mA. The value of β is:

  1. 50
  2. 100
  3. 150
  4. 200

Correct answer: 2. 100


The transistor is a ____________ operated device

The transistor is a ____________ operated device:

  1. Voltage
  2. Current
  3. Both of these
  4. None of these

Correct answer: 2. Current

Correct bias arrangement for a BJT as an amplifier

Which of the following is the correct bias arrangement for a BJT if it is to be operated as an amplifier:

  1. Both Base emitter junction and Base-collector junction are reverse biased
  2. Both Base emitter junction and Base-collector junction are forward biased
  3. Base emitter junction is reverse biased and Base-collector junction is forward biased
  4. Base emitter junction is forward biased and Base-collector junction is reverse biased

Correct answer: 4. Base emitter junction is forward biased and Base-collector junction is reverse biased

What is the value of collector current when the base resistor is open

What is the value of collector current when the base resistor is open

  1. 0 mA
  2. 0.7 mA
  3. 1.5 mA
  4. Infinity

Correct answer: 1. 0 mA

Leave a Comment