Junction Transistors (BJT) Questions and Answers

Practice Mode
Showing 10 of 25 questions
Q21
In which mode does a BJT act like two diodes connected together?
  • A It behaves like two forward-biased diodes
  • B It acts as an ideal current source
  • C It becomes a capacitor
  • D Its junctions break down only
Answer: Option A
Explanation: In saturation both junctions are forward biased making transistor behave like two forward-biased diodes.
Q22
Which measurement gives the DC current gain of a BJT?
  • A β_DC = IC / IB
  • B β_DC = IB / IC
  • C β_DC = VBE / IC
  • D β_DC is independent of currents
Answer: Option A
Explanation: DC current gain is β_DC = IC / IB measured under specified bias conditions.
Q23
What is the consequence of making the base region thicker?
  • A Recombination increases and gain falls
  • B Gain increases drastically
  • C Emitter becomes intrinsic only
  • D No change
Answer: Option A
Explanation: Thicker base increases recombination and reduces current gain since fewer carriers reach the collector.
Q24
Which of the following is true for a transistor used as a switch?
  • A Transistor is either in saturation (ON) or cut-off (OFF)
  • B Transistor always operates in active region
  • C Transistor acts as linear resistor only
  • D Transistor cannot be used as a switch
Answer: Option A
Explanation: When used as a switch, transistor is either in saturation (ON) or cut-off (OFF) to minimize region of linear operation.
Q25
What does the term "beta (β)" refer to in transistor terminology?
  • A Current gain IC/IB (β)
  • B Voltage gain VCE/VBE
  • C Resistance ratio RC/RE
  • D Power gain PC/PE
Answer: Option A
Explanation: Beta (β) is the common-emitter current gain: ratio of collector current to base current (IC/IB).

📚 More from Electronics

← All Topics 🎯 Practice ⏱️ Take Test 🔍 Search
Electronics
Back to Electronics
Other Subjects
Questions and Answers for Competitive Exams Various Entrance Test