Question

The formula R = l / (sigma S) is for thin wires.

(a) True

(b) False

(c) Not necessarily

Answer 1

Gives

Thin wire

$R=\frac{\rho l}{S}\rightarrow(1)$

$\rho=\frac{1}{\sigma}\rightarrow(2)$

equation (1) and (2) we can written as

$R=\frac{ l}{\sigma S}\rightarrow(3)$

equation(3) is true

Option (a) correct