A metal rod consumes power P on passing curreent . If it is cut into two half and joined in parallel, it will consume power

Options

A. P
B. 2P
C. 4P
D. p/4

Answer

C

Explanation

Let the resistance of the rod be R. If the rod is divided into two equal parts, then each part of the rod will have a resistance of R/2. Now these two parts of the rod are connected in parallel and a voltage V is applied across them . Hence the total power consumed is
`p'=(V^(2))/(R//2)+(V^(2))/(R//2)=4(V^(@))/(R)=4P` where
`P=(V^(2))/(R)` is the power consumed by the original rod when voltage V is applied across it.