A metal wire is subjected to a constant potential difference When the temperaturre of the metal in it wire increase the drift velocity of the electrons in it .

Options

A. Increases, thermal velocity of the electron increases
B. Decreases, thermal velocity of the electron increases
C. Increases, thermal velocity of the electron decreases
D. Decreases, thermal velocity of the electron decreases

Answer

B

Explanation

Drift velocity
`v_(d) = ((eE)/m)tau`
As `T uarr tau uarr v_(d) darr`
Thermal velocity
`v_(T) prop sqrt(T), v_("max") = sqrt((3RT)/M)`
As `T uarr v_(T) uarr`