Question

The length of an aluminium bar of lenght 80 cm increases by 1 mm on heating. What is the final temperature of the bar if it was initially at temperature 20 oC? (Given : Coefficient of linear expansion of aluminium = 25 x 10-6 /oc)

Answer 1

ΔT=T-20
l=800mm
Δl=1mm
α=25x10⁻⁶°C
Δl/l=αΔT
1/800=25*10⁻⁶(T-20)
T-20=10⁶/2x10⁴
T-20=0.5x10²
T-20=50
T=70°C
Hope this helps you