ISRO2011-64

Question

When n-type semiconductor is heated?

• A. number of electrons increases while that of holes decreases
• B. number of holes increases while that of electrons decreases
• C. number of electrons and holes remain the same
• D. number of electron and holes increases equally

Answer 1

option B is the answer.

Comments

Is these in syllabus? how to prepare for these kinds of questions? Please do help

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ISRO syllabus is not fixed. But I googled it and found the answer. But , I approach we should study different types of semi-conductor with ie. p and n type with its pros and cons. Then, it will be easier to answer if such questions are asked.

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@Khyatl Shouldn't the answer be (a).N-type semiconductor has excess of electrons than holes and herating up means gaining of energy which means increasing the electrons than holes.Please help to clear my doubt

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I'm unable to find any reference. Could you please give one?

Answer 2

http://www.askiitians.com/forums/IIT-JEE-Entrance-Exam/37/64441/n-type-semiconductor.htm

Here they said Answer is D.

Answer 3

I think the answer is option D.

Here is a reference: https://www.quora.com/What-happens-when-an-n-type-semi-conductor-is-heated-Will-the-number-of-electrons-and-holes-increase-equally

Just think logically... when a metal is heated the charge carriers will get excited -> more free electrons -> more holes

So overall electrons and holes are increased (minority and majority charges increases).