Question

Two wires of same material are having length $L$ and $2L$. Compare their resistance and resistivity.

Answer 1

Resistivity remains the same as it does not depend on the length. Resistivity itself means the resistance offered by a material per unit length and unit area.

While the resistance depends on the length ,

$R_1=\rho \frac{L}{A}$

$R_2=\rho \frac{2L}{A}$

$R_2=2\rho \frac{L}{A}$

$R_2=2R_1$

Thus, the resistance of 2nd wire is twice than that of 1st wire.