Optics Question 657
Question: The focal length of a convex lens is 10 cm and its refractive index is 1.5. If the radius of curvature of one surface is 7.5 cm, the radius of curvature of the second surface will be
[MP PMT 2000]
Options:
A) 7.5 cm
B) 15.0 cm
C) 75 cm
D) 5.0 cm
Show Answer
Answer:
Correct Answer: B
Solution:
$ \frac{1}{f}=(\mu -1)( \frac{1}{R _{1}}-\frac{1}{R _{2}} ) $
$ \Rightarrow $ $ \frac{1}{+10}=(1.5-1)( \frac{1}{+7.5}-\frac{1}{R _{2}} ) $
$ \frac{1}{f _{e}} $
