A) \[f\text{/2}\]
B) \[f\]
C) \[\text{3/2}f\]
D) \[2f\]
Correct Answer: D
Solution :
Let focal length of the lens is f, then \[\frac{1}{f}=\frac{1}{{{f}_{1}}}+\frac{1}{{{f}_{2}}}\] putting \[{{f}_{1}}={{f}_{2}}=f'\] \[\therefore \] \[\frac{1}{f}=\frac{1}{f'}+\frac{1}{f'}\](focal length of each part) \[\Rightarrow \] \[f'=2f\]You need to login to perform this action.
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