Junction Transistors (BJT) Questions and Answers
The Junction Transistors (BJT) questions with answers topic is an integral part of electronics aptitude questions and answers for technical exams such as GATE, DRDO, and BEL. A Bipolar Junction Transistor (BJT) is a semiconductor device used for amplification and switching. Understanding its types (NPN, PNP), working principles, and characteristics is vital for solving objective and circuit-based questions. This section provides solved BJT questions with explanations to help you grasp current gain, transistor biasing, and operating regions effectively.
Junction Transistors (BJT)
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25 questions
21. In which mode does a BJT act like two diodes connected together?
- It behaves like two forward-biased diodes
- It acts as an ideal current source
- It becomes a capacitor
- Its junctions break down only
22. Which measurement gives the DC current gain of a BJT?
- β_DC = IC / IB
- β_DC = IB / IC
- β_DC = VBE / IC
- β_DC is independent of currents
23. What is the consequence of making the base region thicker?
- Recombination increases and gain falls
- Gain increases drastically
- Emitter becomes intrinsic only
- No change
24. Which of the following is true for a transistor used as a switch?
- Transistor is either in saturation (ON) or cut-off (OFF)
- Transistor always operates in active region
- Transistor acts as linear resistor only
- Transistor cannot be used as a switch
25. What does the term "beta (β)" refer to in transistor terminology?
- Current gain IC/IB (β)
- Voltage gain VCE/VBE
- Resistance ratio RC/RE
- Power gain PC/PE