The resistance will be least in a wire with length, cross-section area respectively,

Options

A. L/2, 2A
B. 2L, A
C. L, A
D. L, 2A

Answer

A

Explanation

Resistance `R = rho l ..A` or `R prop l //A`.
`therefore " " R_(a)prop(L)/(4A), R_(b)prop (2L)/(A), R_(c )prop(L)/(A)`.
Thus, resistance is least in a wire of length L/2 and area of cross-section is 2A.