Question

A single slit diffraction pattern is obtained using a beam of red light. If the red light is replaced by blue light, then the diffraction pattern.

• A. Remains unchanged
• B. Becomes narrower
• C. Becomes broader
• D. Will disappear

Answer 1

The correct option is B Becomes narrower

In a single slit diffraction, angular width of diffraction pattern $\sin \theta =\frac{\lambda }{b}$

Since, wavelength of blue light is less than that of red light, so angular width of diffraction pattern is less when blue light is used. So the diffraction pattern becomes narrower.