A constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if

Options

A. both the length and the radius of the wire we halved
B. both the length and the radius of the wire are doulbed
C. The radius of the is doubled
D. the length of the wire is doulbed

Answer

B

Explanation

(b) `P = (V^(2))/(R ) = (V^(2) A)/(rho l) prop (r^(2))/(l) [V rarr same]`