A) \[m=\frac{f}{f-u}\]
B) \[m=\frac{f-u}{f}\]
C) \[m=\frac{f}{f+u}\]
D) \[m=\frac{f+u}{f}\]
Correct Answer: A
Solution :
Magnification, \[m=\frac{-v}{u}\] But \[\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\] (Mirror formula) \[\Rightarrow \] \[\frac{u}{f}=\frac{u}{v}+1\] \[\Rightarrow \] \[-\frac{u}{v}=1-\frac{u}{f}\] \[\Rightarrow \] \[\frac{-v}{u}=\frac{f}{f-u}\] So, \[m=\frac{f}{f-u}\]You need to login to perform this action.
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