Assertion: the value of temperature coefficient of resistance is positive is for metals.
Reason: The temperature coefficient of resistance for insulator is also positive.

Options

A. If both assertion and Reason are true and the Reason is the correct explanation of the assertion.
B. If both assertion and Reason are true but the reason is not the correct explanation of the assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Answer

C

Explanation

On increasing the temperature metals, the resistance of metals increases. Therefore temperature coefficient of resistnace of metals in positive. On increasing the temperature of insulators the resistance decreases. Therefore, temperature coefficient of resistance of insulator is negative.