Optics Question 612
Question: The focal length of convex lens is 30 cm and the size of image is quarter of the object, then the object distance is
[AFMC 1995]
Options:
A) 150 cm
B) 60 cm
C) 30 cm
D) 40 cm
Show Answer
Answer:
Correct Answer: A
Solution:
$ m=\frac{f}{f+u} $
$ \Rightarrow -\frac{1}{4}=\frac{30}{30+u} $
$ \Rightarrow u=-150cm $
