set 9 MCQ Questions & Answers Detailed Explanation

Question : 1

If the conductivity of a semiconductor is only due to break up of the covalent bonds due to thermal excitation, then the semiconductor is called

a) extrinsic

b) donor

c) intrinsic

d) acceptor

Question : 2

Which one of the following is not a correct statement about semiconductors?

a) In an n-type semiconductor, the Fermi level lies closer to the conduction band edge

b) Silicon is a direct band gap semiconductor

c) The electrons and holes have different mobilities in a semiconductor

d) Silicon is has diamond structure

Question : 3

On charging by conduction, mass of a body may

a) decreases

b) increase or decrease

c) increase

d) none of these

Question : 4

Consider the following statements regarding a motor car battery:

1. The voltage is usually 12 V.
2. Electrolyte used is hydrochloric acid.
3. Electrodes are lead and copper.
4. Capacity is expressed in ampere-hour.

a) 3 and 4

b) 1 and 2

c) 2 and 3

d) 1 and 4

Question : 5

Parameters of electricity supply in India are

a) Potential Difference of 220 V, Frequency of 60 hertz and Current Rating of 15A

b) Potential Difference of 220 V, Frequency of 50 hertz and Current Rating of 5A/15A

c) Potential Difference of 150 V, Frequency of 40 hertz and Current Rating of 10 A

d) Potential Difference of 220 V, Frequency of 40 hertz and Current Rating of 5 A