Young’s Double Slit Experiment MCQs
Young’s Double Slit Experiment MCQs
Class: CBSE Class 12
Subject: Physics
Section: Optics
Topic: Young’s Double Slit Experiment
Based on: CBSE Board Examination Pattern (NCERT)
Instructions: These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 12 Board Examination preparation.
1. Young’s Double Slit Experiment demonstrates the ______ nature of light.
Answer: B
YDSE produces interference fringes, proving the wave nature of light.
YDSE produces interference fringes, proving the wave nature of light.
2. Fringe width depends on:
Answer: D
β = λD/d, so it depends on wavelength, screen distance, and slit separation.
β = λD/d, so it depends on wavelength, screen distance, and slit separation.
3. If slit separation increases, fringe width:
Answer: B
β ∝ 1/d. Increasing slit distance reduces fringe width.
β ∝ 1/d. Increasing slit distance reduces fringe width.
4. Bright fringes occur when path difference is:
Answer: A
Constructive interference occurs for integral multiples of wavelength.
Constructive interference occurs for integral multiples of wavelength.
5. Dark fringes occur when path difference is:
Answer: B
Destructive interference occurs for odd multiples of λ/2.
Destructive interference occurs for odd multiples of λ/2.
6. Central fringe in YDSE is:
Answer: B
Path difference at center is zero → constructive interference.
Path difference at center is zero → constructive interference.
7. Coherent sources have same:
Answer: A
Constant phase difference is essential for stable fringes.
Constant phase difference is essential for stable fringes.
8. Fringe width unit is:
Answer: A
Fringe width is a linear distance.
Fringe width is a linear distance.
9. If wavelength increases, fringe width:
Answer: B
β ∝ λ, so larger wavelength → wider fringes.
β ∝ λ, so larger wavelength → wider fringes.
10. Shape of interference fringes is:
Answer: C
Near screen center, fringes appear straight and parallel.
Near screen center, fringes appear straight and parallel.
11. Source used in YDSE must be:
Answer: C
Stable interference requires coherent monochromatic light.
Stable interference requires coherent monochromatic light.
12. If screen distance doubles, fringe width:
Answer: B
β ∝ D, so fringe width increases.
β ∝ D, so fringe width increases.
13. Interference pattern disappears if slits are:
Answer: C
Without coherence, phase relation is random.
Without coherence, phase relation is random.
14. Angular fringe width equals:
Answer: A
Angular width θ = λ/d.
Angular width θ = λ/d.
15. If slit width increases greatly, fringes become:
Answer: B
Large slit width reduces diffraction → poor interference visibility.
Large slit width reduces diffraction → poor interference visibility.
16. Phase difference for first bright fringe:
Answer: C
First bright fringe corresponds to phase difference 2π.
First bright fringe corresponds to phase difference 2π.
17. Interference is maximum when amplitudes are:
Answer: A
Equal amplitudes produce highest contrast fringes.
Equal amplitudes produce highest contrast fringes.
18. Distance between consecutive bright fringes is:
Answer: A
This distance defines fringe width.
This distance defines fringe width.
19. White light in YDSE produces:
Answer: B
Different wavelengths form colored fringes.
Different wavelengths form colored fringes.
20. YDSE was first performed by:
Answer: B
Thomas Young demonstrated interference in 1801.
Thomas Young demonstrated interference in 1801.