A) 20 cm
B) 40 cm
C) 30 cm
D) 10 cm
Correct Answer: D
Solution :
\[\frac{1}{F}=\frac{2}{{{f}_{l}}}+\frac{1}{{{f}_{m}}}\]\[\Rightarrow \]\[\frac{1}{F}=\frac{2}{20}+\frac{1}{\infty }\Rightarrow F=10\]\[cm\]You need to login to perform this action.
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