A constant voltage is applied between two ends of a metallic wire if the length is halved and the radius of the wire is doubled the rate of heat developed in the wire will be :

Options

A. be halved
B. be doubled
C. remain the same
D. be quadrupled

Answer

B

Explanation

`P = (V^(2))/( R ) or P = ( V^(2) a)/( rho l) = (V^(2) pi r^(2))/( rho l)`