A) \[32\pi {{R}^{2}}T\]
B) \[24\pi {{R}^{2}}T\]
C) \[8\pi {{R}^{2}}T\]
D) \[4\pi {{R}^{2}}T\]
Correct Answer: B
Solution :
Initial surface energy \[{{U}_{1}}=2\times 4\pi {{R}^{2}}T=8\pi {{R}^{2}}T\] Final surface energy \[{{U}_{2}}=2\times 4\pi {{(2R)}^{2}}T=32\pi {{R}^{2}}T\] Hence, required energy \[=32\pi {{R}^{2}}T-8\pi {{R}^{2}}T\] \[=24\pi {{R}^{2}}T\]You need to login to perform this action.
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