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CUET · PHYSICS · PYQ PAPER 2025

In a diffraction pattern due to a narrow slit of width a, alternate dark and bright fringe pattern is obtained on a screen kept at distance D from the slit. Choose the correct option.
(A) The angular width of central maximum is given by 2D/a, linear width is given by 2D\lambda/a
(B) When the size of aperture, a is quite large, the diffraction effect is negligible,
(C) For light of smaller wavelength, angular width of central maximum increases, while linear width decreases,
(D) Angular width of central maximum does not decrease while linear width decreases on decreasing distance of screen from slit.
Choose the correct answer from the options given below:

  1. A (A) and (B) only
  2. B (A) and (C) only
  3. C (B) and (C) only
  4. D (B) and (D) only
Verified Solution

Answer & Solution

Correct Answer

(D) (B) and (D) only

Step-by-step Solution

Detailed explanation

Angular width of central maximum: \( \theta = 2\lambda/a \). Linear width of central maximum: \( W = 2D\lambda/a \). (A) Angular width \( 2D/a \) is incorrect. (A) is incorrect. (B) When aperture size \( a \) is large, diffraction is negligible. (B) is correct. (C) For smaller…