A) \[\frac{10}{3}\]cm
B) 30 cm
C) 15 cm
D) \[\frac{100}{3}\]cm
Correct Answer: B
Solution :
For improving far point, concave lens is required and for this concave lens \[u=\infty ,\ \ v=-\ 30\ cm\] So \[\frac{1}{f}=\frac{1}{-30}-\frac{1}{\infty }\Rightarrow f=-\ 30\ cm\] for near point \[\frac{1}{-30}=\frac{1}{-15}-\frac{1}{u}\Rightarrow u=-\ 30\ cm\]You need to login to perform this action.
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