Optics Question 665
Question: An object is placed 12 cm to the left of a converging lens of focal length 8 cm. Another converging lens of 6 cm focal length is placed at a distance of 30 cm to the right of the first lens. The second lens will produce
[KCET 2002]
Options:
A) No image
B) A virtual enlarged image
C) A real enlarged image
D) A real smaller image
Show Answer
Answer:
Correct Answer: C
Solution:
For lens (1) $ \frac{1}{f}=\frac{1}{v}-\frac{1}{u}\Rightarrow \frac{1}{(+8)}=\frac{1}{v}-\frac{1}{(-12)} $
$ \Rightarrow v=24 $ $ cm $ i.e.
Image $ A’B’ $ is obtained 6 cm before the lens 2 or at the focus of lens 2.
Hence final image formed by lens 2 will be real enlarged and it is obtained at $ \infty $ .
