Question

In case of Fraunhofer diffraction on a single slit the diffraction pattern on the screen correct for which of the following statements ?

• A. Central dark band having uniform brightness on either side.
• B. Central dark band having alternate dark and bright bands of decreasing intensity on either side.
• C. Central bride band having dark bands on either sides.
• D. Central bride band having alternate dark and bright bands of decreasing intensity on either side.

Answer 1

The Correct Option is D

When a single slit is illuminated by a coherent light source, such as a laser, the diffracted light waves interfere with each other, resulting in a pattern of alternating dark and bright bands on the screen. The central bright band is the brightest part of the pattern and is flanked by dark bands on either side. The intensity of the bright bands gradually decreases as you move away from the central bright band. 
This pattern arises due to the constructive and destructive interference of the diffracted waves. The central bright band occurs when the waves from different parts of the slit arrive at the same phase and interfere constructively. The adjacent dark bands occur when the waves arrive at the opposite phase and interfere destructively. The alternating nature of the pattern is a result of the interference between the diffracted waves. 
Therefore, option (D) accurately describes the diffraction pattern observed in Fraunhofer diffraction on a single slit.