Width of two slits in Young's double slits experiment are in the ratio 9 : 4. The ratio of the amplitudes of light waves through them would be:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 3 : 2
The light passing through a slit is proportional to its width, so the intensity from each slit is proportional to its width. The intensity is proportional to the square of the amplitude, \( I\propto A^{2} \).
\( \displaystyle \frac{w_1}{w_2} = \frac{I_1}{I_2} = \frac{A_1^{2}}{A_2^{2}} = \frac{9}{4} \)
\( \displaystyle \frac{A_1}{A_2} = \sqrt{\frac{9}{4}} = \frac{3}{2} \)