Optics Question 929
Question: An object is placed at $ 20cm $ from a convex mirror of focal length $ 10cm. $ The image formed by the mirror is
[JIPMER 1999]
Options:
A) Real and at $ 20cm $ from the mirror
B) Virtual and at $ 20cm $ from the mirror
C) Virtual and at $ 20/3cm $ from the mirror
D) Real and at $ 20/3cm $ from the mirror
Show Answer
Answer:
Correct Answer: C
Solution:
$ u=-20cm, $
$ f=+10cm $ also $ \frac{1}{f}=\frac{1}{v}+\frac{1}{u} $
$ \Rightarrow \frac{1}{+10}=\frac{1}{v}+\frac{1}{(-20)}\Rightarrow v=\frac{20}{3}cm; $ virtual image.
