Q. If separation between screen and source is increased by 2% what would be the effect on the intensity
A) Increases by 4%
B) Increases by 2%
C) Decreases by 2%
D) Decreases by 4%
Explanation
(d) $I \propto \frac{1}{r^{2}} \Rightarrow \frac{\mathrm{\Delta}I}{I} = - 2\frac{\mathrm{\Delta}r}{r} = - 2 \times 2 = - 4\%$
Hence intensity is decreased by 4%
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.