The depletion region of a pn junction is a layer that
Correct answer: B. has been swept clear of mobile charge carriers, leaving fixed ions and a potential barrier
- A. contains a very high concentration of free carriers
- B. has been swept clear of mobile charge carriers, leaving fixed ions and a potential barrier
- C. conducts better than the rest of the crystal
- D. consists only of electrons
Explanation
Electrons diffusing across the junction recombine with holes, leaving exposed fixed ions on both sides and a region with almost no mobile carriers, so it acts as an insulator. The resulting internal field forms a potential barrier of about 0.7 V for silicon and 0.3 V for germanium. Forward biasing narrows this region and reverse biasing widens it.
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
The majority charge carriers in a p type semiconductor are
A semiconductor doped with a pentavalent impurity such as phosphorus becomes
A pn junction diode is forward biased when
In reverse bias, the current through an ideal diode is
The barrier potential across an unbiased silicon pn junction is about
A Zener diode is normally operated