Q. A diffraction pattern is obtained using a beam of red light. What happens if the red light is replaced by blue light
A) No change
B) Diffraction bands become narrower and crowded together
C) Band become broader and farther apart
D) Bands disappear altogether
Explanation
(b) As $\lambda_{blue} < \lambda_{red}$ and width of diffraction bands is directly proportional to $\lambda$, therefore diffraction bands become narrower and crowded
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.