Question

A thin copper wire of length `l` metre increases in length by `2%` when heated through `10^(@)C`. What is the percentage increase in area when a square copper sheet of length `l` metre is heated through `10^(@)C`
A. `4%`
B. `8%`
C. `16%`
D. None of these

Answer 1

Correct Answer - A
`A =l^(2) rArr (Delta A)/(A) xx 100 = 2(Delta l)/(l) xx 100 =2 (2 %) = 4%