Q. In Young’s double slit experiment the amplitudes of two sources are $3a$ and $a$ respectively. The ratio of intensities of bright and dark fringes will be
A) 3 : 1
B) 4 : 1
C) 2 : 1
D) 9 : 1
Explanation
(b) $\frac{I_{\max}}{I_{\min}} = \left( \frac{a_{1} + a_{2}}{a_{1} - a_{2}} \right)^{2} = \left( \frac{3a + a}{3a - a} \right)^{2} = \frac{4}{1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.