A) inversely proportional to the cross-sectional area of the bar
B) independent of the length of the bar
C) inversely proportional to the length of the bar
D) directly proportional to the length of the bar
Correct Answer: B
Solution :
When force F is applied \[\Upsilon =\frac{FL}{Al}\]where \[\Upsilon \] is Youngs modulus, A is area \[F=\frac{\Upsilon Al}{L}\] ...(1) From the formula for linear expansion \[\alpha =\frac{l}{L\times 100}\] ...(2) According to the condition mat bar will not bend or expand Now from equations (1) and (2) \[F=\Upsilon A\times 100\,\alpha \] Hence, force is independent of length LYou need to login to perform this action.
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