Consider a rectangular slab of length L, and area of cross-section A. A current I is passed through it if the length is doubled the potential drop across the end faces

Options

A. Becomes half of the initial value
B. Becomes one-fourth of the initial value
C. Becomes double the initial value
D. Remains same

Answer

C

Explanation

`R = (rho l)/A rArr R prop l`
`rArr R_(1)/R_(2) = l/(2l) rArr R_(2) = 2R_(1)`
From V = IR, potential drop is of 2V.