Question

In a single slit diffraction pattern, identify the incorrect statement from the following.

• A. The fringes have unequal width.
• B. The fringes have unequal intensity.
• C. The fringes have unequal width and unequal intensity.
• D. The fringes have equal width and equal intensity.

Hint:

Single slit diffraction is different from ideal interference. Its fringes are not equal in both width and intensity.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Single slit diffraction differs from interference. It produces a broad central maximum and smaller secondary maxima on either side.
Step 2: Detailed Explanation:
(A) Correct fact: In diffraction, the central maximum is twice as wide as the secondary maxima. Widths are unequal.
(B) Correct fact: The intensity of the central maximum is much higher, and it decreases rapidly for subsequent orders. Intensities are unequal.
(C) Correct fact: This is a combination of A and B, which correctly describes diffraction.
(D) Incorrect fact: Fringes of equal width and intensity are characteristic of ideal two-slit interference (YDSE), not diffraction.
Step 3: Final Answer:
The incorrect statement is (D).