question_answer

A compressive force, F is applied at the two ends of a long thin steel rod. It is heated, simultaneously, such that its temeprature increases by \[\Delta T.\] The net change in its length is zero. Let l be the length of the rod, A its area of cross-section, Y its Young's modulus, and \[\alpha \] its coefficient of linear expansion. Then, F is equal to- [JEE Online 08-04-2017]

A) \[IAY\alpha \Delta T\]     

B)      \[AY\alpha \Delta T\]

C) \[\frac{AY}{\alpha \Delta T}\]    

D)      \[{{I}^{2}}Y\alpha \Delta T\]

Correct Answer: C

Solution :

[c] Net change in length = 0

Thermal Exp.