Length of an iron rod at 270C is 10m α=11×10−6 . To decrease the length of the rod by 1.1 mm, a temperature of the rod should be decreased to:
l=10m
T=270c
l2=l1(l+αΔT)
l2=l1+αl1ΔT
(l2−l1)l1=α(T2−T1)
1.1×10−310=11×10−6(T2−27)
T2=70c
The co-efficient of linear expansion of iron is 11/180 of volume coefficient of expansion of mercury which is 18×10−5/0C. An iron rod is 10m long at 270 C. The length of the rod will be decreased by 1.1 mm when the temperature of the rod changes by
An Iron rod and a copper rod lie side by side. As the temperature is changed, the difference in the lengths of the rods remains constant at a value of 10 cm. Find the lengths at 0∘C. Coefficients of linear expansion of iron and copper are 1.1 × 10−6/∘C and 1.7 × 10−5/∘C respectively.