Ray Optics Question 14
Question 14 - 01 February - Shift 2
Two objects A and B are placed at $15 cm$ and 25 $cm$ from the pole in front of a concave mirror having radius of curvature $40 cm$. The distance between images formed by the mirror is:
(1) $40 cm$
(2) $60 cm$
(3) $160 cm$
(4) $100 cm$
Show Answer
Answer: (3)
Solution:
Formula: Mirror Formula
by mirror formula
$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$
$\frac{1}{v_1}+\frac{1}{-15}=\frac{1}{(-20)}$
$\frac{1}{v_1}=-\frac{1}{20}+\frac{1}{15}$
$=\frac{-3+4}{60}$
$v_1=60 cm$
$\frac{1}{v_2}+\frac{1}{(-25)}=\frac{1}{(-20)}$
$\frac{1}{v_2}=\frac{-1}{20}+\frac{1}{25}$
$=\frac{-5+4}{m}=-1$
$ d=60+100=160 cm $
