Q. A single slit is used to observe diffraction pattern with red light. On replacing the red light with violet light the diffraction pattern would
A) Remain unchanged
B) Become narrower
C) Become broader
D) Disappear
Explanation
(b) In diffraction pattern, fringe width is proportional to $\lambda.$ We know that wavelength of violet light is less than that of red light, so on replacing red light with violet light, diffraction pattern would become narrower.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.