A) 0.014 J
B) 0.028 J
C) 0.01 J
D) 0.007 J
Correct Answer: A
Solution :
\[M\,=\,{{10}^{-2}}\widehat{i}\] \[B=1\,cos\,\left( 0.125t \right)\widehat{i}\] \[at\text{ }t=1\text{ }sec\] \[B=1\,\,cos\left( 0.125 \right)\text{ }\widehat{i}\] \[=\,\,\cos \left( \frac{125}{1000} \right)\widehat{i}\,=\,\cos \,\left( \frac{1}{8} \right)\widehat{i}\] = 1 \[{{W}_{ext}}=\left[ -MB\text{ }cos\text{ }180{}^\circ -\left( -MB\text{ }cos\text{ }0{}^\circ \right) \right]\] \[=\text{ }MB+MB=2MB\] \[=\text{ }2\times {{10}^{-}}^{2}\times cos\left( \frac{1}{8} \right)=0.019\]You need to login to perform this action.
You will be redirected in
3 sec