A) 36 cm
B) 25 cm
C) 30 cm
D) 150 cm
Correct Answer: A
Solution :
We have a lens of focal, length 30 cm that produces 5 times magnified real image. So, we have \[\frac{1}{5u}-\left( \frac{1}{-u} \right)=\frac{1}{30}\] Hence, \[\frac{1}{5u}+\frac{1}{u}=\frac{5+1}{5u}\] \[=\frac{1}{30}\] So, \[u=36\,cm\]You need to login to perform this action.
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