Question

If the length of a metal wire of resistivity R is doubled and it's area is reduced to half. What would be the resistivity of the new wire.​

Answer 1

Explanation:

For the first wire R1- (rho) l/A = x ohm.

Now for the second wire,

R2- (rho) 2l/ 0.5A= 4 (rho) l/A

Therefoe R2 - 4 x ohm.