The increase in energy of a metal bar of length ‘L’ and cross-sect

1.	The increase in energy of a metal bar of length ‘L’ and cross-sectional area ‘A’ when compressed with a load ‘M’ along its length is (Y = Young’s modulus of the material of metal bar)(A) \(\frac{FL}{2AY}\)(B) \(\frac{F^2L}{2AY}\)(C) \(\frac{FL}{AY}\)(D) \(\frac{F^2L^2}{2AY}\)
Answer» (B) \(\frac{F^2 L}{2AY}\) U = \(\frac{1}{2}\) × F × l = \(\frac{1}{2}\) × F × \(\frac{FL}{AY}=\frac{F^2 L}{2AY}\)

The increase in energy of a metal bar of length ‘L’ and cross-sectional area ‘A’ when compressed with a load ‘M’ along its length is (Y = Young’s modulus of the material of metal bar)(A) \(\frac{FL}{2AY}\)(B) \(\frac{F^2L}{2AY}\)(C) \(\frac{FL}{AY}\)(D) \(\frac{F^2L^2}{2AY}\)

Answer»

(B) \(\frac{F^2 L}{2AY}\)

U = \(\frac{1}{2}\) × F × l

= \(\frac{1}{2}\) × F × \(\frac{FL}{AY}=\frac{F^2 L}{2AY}\)