Question
Physics Question on spherical lenses
A point object is moving at a constant speed of 1 ms-1 along the principal axis of a convex lens of focal length 10cm. The speed of the image is also 1 ms-1 , when the object is at _______ cm from the optic centre of the lens.
A
15
B
20
C
5
D
10
Answer
20
Explanation
Solution
The correct answer is (B) : 20.