99 Percentile Qs Bank for JEE MainPhysicsThermal Properties of Matter
A metal rod of length L and cross-sectional area A is heated through T ^ C . What is the force required to prevent the expansion of the rod lengthwise? (Y= Young's modulus of material of the rod, = coefficient of linear expansion of the rod.)
Options
- AYA / T (1+ T )
- BYA T /(1- T )
- CYA T /(1+ T )
- DYA /(1- T )
Correct answer
C. YA T /(1+ T )
Step-by-step solution
The increase in length due to heating is given by L = L ₀(1+ T ) or L - L ₀= L = L ₀ T To compress the rod by L , the force required is given by F = YA L L Substituting the value of L and L we get F = YA L ₀ T L _ o (1+ T ) = YA T 1+ T