Question

A wire is stretched 50%, Calculate % change in its resistance.

Answer 1

When a wire is stretched then its volume will remain same, and we know the relation—

R₂/R₁ = (L₂/L₁)²

Here, it is given that the wire is stretched 50%, So, We can write—

Change in resistance,R = R₂ – R₁

= 2.25 R₁ – R₁

= R₁ (2.25 – 1)

= R₁ x 1.25

% Change in resistance = change in resistance/ original resistance x 100