A transistor is used as an amplifier because a small change in the base current produces

Correct answer: B. a much larger change in the collector current

  • A. no change in the collector current
  • B. a much larger change in the collector current
  • C. a smaller change in the collector current
  • D. a change only in the emitter voltage

Explanation

The current gain of a common emitter transistor is typically between 50 and 300, so a weak input signal at the base controls a much larger collector current and the extra energy comes from the power supply. The transistor does not create energy; it controls the flow of it. Used in saturation and cut off instead, the same device acts as a switch.

Written and checked by , contributorLast updated
Report an error

The more specific you are, the faster it gets fixed. A source beats an opinion.

Prefer email? support@testustad.com

About PN Junction

A PN junction forms when p type and n type semiconductor regions meet, creating a depletion layer and a potential barrier. The topic covers forward and reverse bias, diode current voltage characteristics, breakdown and rectification, while distinguishing an ordinary junction diode from a transistor formed from multiple junctions.

Practise Electronics

660 free Electronics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Discussion

Stuck on an option, or know a faster way to get there? Ask or explain it here.

No comments yet. Be the first to explain this one.

Exams that ask Physics questions like this

Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

More PN Junction questions