Question
Question: If a convex lens of focal length 40 cm forms real image of an object over a screen at 180 cm from th...
If a convex lens of focal length 40 cm forms real image of an object over a screen at 180 cm from the object for two positions of lens between object and the screen. The distance between two positions is –
A
40 cm
B
80 cm
C
60 cm
D
90 cm
Answer
60 cm
Explanation
Solution
u = \ u = 120 cm, 60 cm
\ Required distance = 120 – 60 = 60 cm