Optics Question 902
Question: A convex mirror of focal length f forms an image which is $ \frac{1}{n} $ times the object. The distance of the object from the mirror is
Options:
A) $ (n-1)f $
B) $ ( \frac{n-1}{n} )f $
C) $ ( \frac{n+1}{n} )f $
D) $ (n+1)f $
Show Answer
Answer:
Correct Answer: A
Solution:
$ m=+\frac{1}{n}=-\frac{v}{u}\Rightarrow v=-\frac{u}{n} $ .
By using mirror formula $ \frac{1}{f}=\frac{1}{-\frac{u}{n}}+\frac{1}{u} $
$ \Rightarrow u=-(n-1)f $
