A wire is stretched to increase its length by 5%. Calculate percentage change in its resistance.

Explanation

When a wire is stretiched its volume remains constants hence
now `r_(1)=(pl_(1))/(A)=(pl_(1))xx(l_(1))/(l_(1)A_(1))=(pl_(1)^(2))/I(v )i.e R_(1) prop l_(1)^(2)`
`R_(2) =1.025 R_(1)`
`=(1.1025-1)xx100=10.25 %`