Question

The radius of a circular sheet of copper measured at 25°C was 20 cm. The change in area of the sheet when temperature is increased ti thrice the initial temperature is.(Coefficient of linear expansion of copper is 17 x 106/°C​

Answer 1

Explanation:

Initial area A=π(35)

2

=3846.5cm

2

Change in area on heating ΔA=14.5cm

2

α=1.7×10

−5

We know that area expansion coefficient is twice of linear expansion coefficient.

So β=2α=2×1.7×10

−5

=3.4×10

−5

So ΔA=AβΔt

14.5=3846.5×3.4×10

−5

×ΔT

ΔT=110.8

o

C