Optics Question 133
Question: The separation between the screen and a plane mirror is 2r. An isotropic point source of light is placed exactly midway between the mirror and the screen. Assume that mirror reflects 100% of incident light. Then the ratio of illuminances on the screen with and without the mirror is
Options:
A) 10 : 1
B) 2 : 1
C) 10 : 9
D) 9 : 1
Show Answer
Answer:
Correct Answer: C
Solution:
The illuminance on the screen without mirror is
The illuminance on the screen with mirror is
