A) \[40\sqrt{3}\]
B) 40
C) 20
D) \[40\times {{10}^{-4}}\]
Correct Answer: B
Solution :
\[I=\frac{L\cos \theta }{{{r}^{2}}}\] \[\Rightarrow \ \ L=\frac{I\times {{r}^{2}}}{\cos \theta }\] \[=\frac{5\times {{10}^{-4}}\times {{10}^{4}}\times {{2}^{2}}}{\cos 60{}^\circ }\ =\ 40\ Candela\]You need to login to perform this action.
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