A) \[K({{l}_{2}}-{{l}_{1}})\]
B) \[\frac{K}{2}({{l}_{2}}+{{l}_{1}})\]
C) \[K(l_{2}^{2}-l_{1}^{2})\]
D) \[\frac{K}{2}(l_{2}^{2}-l_{1}^{2})\]
Correct Answer: D
Solution :
At extension \[{{l}_{1}}\], the stored energy \[=\frac{1}{2}Kl_{1}^{2}\] At extension \[{{l}_{2}}\], the stored energy\[=\frac{1}{2}Kl_{2}^{2}\] Work done in increasing its extension from \[{{l}_{1}}\] to \[{{l}_{2}}\] \[=\frac{1}{2}K(l_{2}^{2}-l_{1}^{2})\]You need to login to perform this action.
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