Optics Question 628
Question: A convex lens of focal length 0.5 m and concave lens of focal length 1 m are combined. The power of the resulting lens will be
[CPMT 1999; JIPMER 2000]
Options:
A) 1 D
B) - 1 D
C) 0.5 D
D) -0.5 D
Show Answer
Answer:
Correct Answer: A
Solution:
$ P=P _{1}+P _{2} $
$ =\frac{1}{f _{1}}+\frac{1}{f _{2}}=\frac{1}{(0.5)}+\frac{1}{(-1)}=1D $
