A) 6 cm
B) 4.5 cm
C) 9 cm
D) 4 cm
Correct Answer: B
Solution :
\[\frac{1}{f}=(\mu -1)\left\{ \frac{1}{{{R}_{1}}}-\frac{1}{{{R}_{1}}} \right\}\]or \[\frac{1}{6}(1.5-1)\left\{ \frac{1}{R}+\frac{1}{2R} \right\}\] \[\Rightarrow \]\[R=4.5\,cm.\] Hence, the correction option is (b).You need to login to perform this action.
You will be redirected in
3 sec