Assertion : When the temperature of a semiconductor is increased, then its resistance decreases.
Assertion : When the temperature of a semiconductor is increased, then its resistance decreases.
Reason: The energy gap between conduction band and valence band is very small.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not correct explanation of A
(c) A is true but R is false
(d) A and R are false
1 Answers
The correct option is (a).
Explanation:
The energy gap between the valence and the conduction band is very small, so by raising the temperature we can get more electrons flipping from valence to conduction band thereby increasing the carriers of electricity in the semiconductors. That's why in semiconductors we have negative temperature coefficient of resistance and so the resistance decreases with temperature.