Assertion : The drift velocity of electrons in a metallic wire will decrease, if the temperature of the wire is increased.
Reason : On increasing temperature, conductivity of metallic wire decreases.

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

Answer

B

Explanation

`v_(d) = ((-eE)/m) tau`
`tau rArr` Relaxation time.
`T uarr tau darr v_(d) darr rho uarr sigma darr`