On increasing the temperature of a conductor, its resistance increases because

Options

A. relaxation time increases
B. electron density decreases
C. relaxation time decreases
D. relaxation time remains constant

Answer

C

Explanation

Resistance of a conductor, `R=(m)/(n e^(2)tau)(l)/(A)`
where the symbols have their usual meaning.
As the temperature increases, the relaxation time `tau` decreases.