A cylindrical conductor of length `l` and uniform area of cross-section `A` has resistance `R`. Another conductor of length `2 l` and resistance `R` of the same material has area of cross-section :

Options

A. `A//2`
B. `3 A//2`
C. `2 A`
D. `3 A`

Answer

C

Explanation

As `R = (rho l)/(A)`, when `l` becomes `2 l`, A should be `2 A` so that `R` remains the same.