A) \[4\pi ({{D}^{2}}-{{d}^{2}})T\]
B) \[8\pi ({{D}^{2}}-{{d}^{2}})T\]
C) \[\pi ({{D}^{2}}-{{d}^{2}})T\]
D) \[2\pi ({{D}^{2}}-{{d}^{2}})T\]
Correct Answer: D
Solution :
\[W=T\times 8\pi (r_{2}^{2}-r_{1}^{2})=T\times 8\pi \left( \frac{{{D}^{2}}}{4}-\frac{{{d}^{2}}}{4} \right)\] \[=2\pi ({{D}^{2}}-{{d}^{2}})T\]You need to login to perform this action.
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