Question

A thin copper wire of length l metre increases in length by 2% when heated through 10ŗC. What is the percentage increase in area when a square copper sheet of length l metre is heated through 10ŗC?

• A. (a) 4%
• A. (b) 8%
• A. (c) 16%
• A. (d) None of the above

Answer 1

(a)

Sol. Since percentage increase in length = 2 %

Hence, percentage increase in area of square sheet

$= 2 \times 2 \%$ = 4%