Optics Question 643
Question: A convex lens of focal length $ f $ produces an image $ \frac{1}{n} $ times than that of the size of the object. The distance of the object from the lens is
[BHU 1997; JIPMER 2001, 02]
Options:
A) $ nf $
B) $ \frac{f}{n} $
C) $ (n+1)f $
D) $ (n-1)f $
Show Answer
Answer:
Correct Answer: C
Solution:
$ m=\frac{f}{(f+u)}\Rightarrow -\frac{1}{n}=\frac{f}{(f+u)} $
$ \Rightarrow u=-\ (n+1)f $
