A) -10 cm
B) 20 cm
C) -30 cm
D) 5 cm
Correct Answer: C
Solution :
Given \[u=10\,cm,\,v=15\,cm\] \[\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\] \[\frac{1}{f}=\frac{1}{15}-\frac{1}{10}\] \[\frac{1}{f}=\frac{10-15}{150}\] \[\frac{1}{f}=\frac{-5}{150}\] \[f=-30\,cm\]You need to login to perform this action.
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