Wave Mechanics Question 1097
Question: If separation between screen and source is increased by 2% what would be the effect on the intensity
[CPMT 2003]
Options:
A) Increases by 4%
B) Increases by 2%
C) Decreases by 2%
D) Decreases by 4%
Show Answer
Answer:
Correct Answer: D
Solution:
$ I\propto \frac{1}{r^{2}} $
Therefore $ \frac{\Delta I}{I}=-2\frac{\Delta r}{r} $ =$ -,2\times 2=-,4,% $ Hence intensity is decreased by 4%.