A) 2 sin A
B) \[2\cos A\]
C) \[\left( \frac{1}{2} \right)\cos A\]
D) \[\tan A\]
Correct Answer: B
Solution :
The refracted ray BC will retrace its path if it falls normally on the silvered face PQ of the prism, i.e.,\[\angle PCB={{90}^{o}}\] \[\therefore \]\[\alpha ={{90}^{o}}-A\] \[\therefore \]\[r=90-\alpha =90-(90-A)=A\] Now, \[\mu =\frac{\sin i}{\sin r}=\frac{\sin 2A}{\sin A}=2\cos A\] Hence, the correction option is (b).You need to login to perform this action.
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