Interference of Light MCQs Type Questions with Answer for ISC Class 12 . These MCQs / Objective Type Questions is based on latest reduced syllabus according 2021-22 session on bifurcated pattern. Main motto of MCQ Type Question is cracking the next upcoming Sem-2 exam of council. Visit official website CISCE for detail information about ISC Class-12 Physics.
ISC Class 12 Interference of Light MCQs Type Questions with Answer
| Board | ISC |
| Class | 12th (XII) |
| Subject | Physics |
| Chapter | Interference of Light |
| Syllabus | on bifurcated syllabus (after reduction) |
| Session | 2021-22 |
| Bifurcated | Sem-2 |
| Topic | MCQs / Objective Type Question |
MCQs Interference of Light ISC Class 12 Physics
Question 1. In Young’s double-slit experiment with monochromatic light, how is fringe width affected, if the screen is moved closer to the slits?
(a) Independent
(b) Remains the same
(c) Increases
(d) Decreases
Answer: (c) Increases
Question 2. Fringe width in Young’s double slit experiment, increases when:
(a) separation between sources increases
(b) distance between source and screen increases
(c) wavelength of light decreases
(d) do not change
Answer: (b) distance between source and screen increases
Question 3. Actual shape of interference fringes is:
(a) parabolic
(b) hyperbolic
(c) straight
(d) none
Answer: (b) hyperbolic
Question 4. In Young’s double slit experiment, if the monochromatic source of yellow light is replaced by red light, the fringe width
(a) increases
(b) decreases.
(c) remains unchanged.
(d) the fringes disappear
Answer: (a) increases
Question 5. Zero order fringe can be identified using _______
(a) White light
(b) Yellow light
(c) Achromatic light
(d) Monochromatic light
Answer: (a) White light
Question 6. Interference is observed only when the phase difference between the two waves is zero.
(a) True
(b) False
Answer: (b) False
Question 7. The phenomenon of interference is based on
(a) conservation of momentum.
(b) conservation of energy.
(c) conservation of momentum and energy.
(d) quantum nature of light.
Answer: (b) conservation of energy.
Question 8. When interference of light takes place
(a) energy is created in the region of maximum intensity
(b) energy is destroyed in the region of maximum intensity
(c) conservation of energy holds good and energy is redistributed
(d) conservation of energy does not hold good
Answer: (c) conservation of energy holds good and energy is redistributed
Question 9. What would be the resultant intensity at a point of destructive interference, if there are two identical coherent waves of intensity I0 producing an interference pattern?
(a) 5 I0
(b) 2 I0
(c) I0
(d) zero
Answer: (d) zero
Question 10. When Two waves of same amplitude add constructively, the intensity becomes ________
(a) Double
(b) Half
(c) Four Times
(d) One-Fourth
Answer: (c) Four Times
Question 11. The shape of the fringes observed in interference is ________
(a) Straight
(b) Circular
(c) Hyperbolic
(d) Elliptical
Answer: (c) Hyperbolic
Question 12. Two independent light sources act as coherent sources’.
(a) True
(b) False
Answer: (b) False
Question 13. What will be the effect on the fringes formed in Young’s double-slit experiment if the apparatus is immersed in water?
(a) Increases
(b) Decreases
(c) Remains the same
(d) Independent
Answer: (b) Decreases
Question 14. In Young’s double-slit experiment if the distance between two slits is halved and distance between the slits and the screen is doubled, then what will be the effect on fringe width?
(a) Doubled
(b) Decreases four times
(c) Increases four times
(d) Halved
Answer: (c) Increases four times
Question 15. If two coherent sources are vibrating in phase then we have constructive interference at any point P whenever the path difference is
(a) (n+1/2)λ
(b) nλ/2
(c) (n-1/2)λ
(d) nλ
Answer: (d) nλ
Question 16. If the separation between the two slits is decreased in Young’s double-slit experiment keeping the screen position fixed, what will happen to the width of the fringe?
(a) Decreases
(b) Increases
(c) Remains the same
(d) Independent
Answer: (b) Increases
Question 17. When exposed to sunlight, thin films of oil on water of ten exhibit brilliant colours due to the phenomenon of
(a) interference
(b) diffraction
(c) dispersion
(d) polarisation
Answer: (a) interference
Question 18. A double slit interference experiment is carried out in air and the entire arrangement is dipped in water. The fringe width
(a) increases
(b) decreases
(c) remains unchanged.
(d) fringe pattern disappears.
Answer: (b) decreases
Question 19. In Young’s double-slit experiment, lights of green, yellow, and orange colors are successively used. Write the fringe widths for the three colors in increasing order.
(a) βG < βY < βO
(b) βO < βY < βG
(c) βO < βG < βY
(d) βY < βG < βO
Answer: (b) βO < βY < βG
Question 20. In Young’s double-slit experiment, the two parallel slits are made one millimeter apart and a screen is placed one meter away. What is the fringe separation when blue-green light of wavelength 500 nm is used?
(a) 0.5 mm
(b) 50 mm
(c) 0.25 mm
(d) 25 mm
Answer: (a) 0.5 mm
Question 21. In a double slit interference pattern, the first maxima for infrared light would be
(a) at the same place as the first maxima for green light
(b) closer to the centre than the first maxima for green light
(c) farther from the centre than the first maxima for green light
(d) infrared light does not produce an interference pattern
Answer: (c) farther from the centre than the first maxima for green light
Question 22. What happens to the interference pattern if the phase difference between the two sources varies continuously?
(a) Brightens
(b) No change
(c) Disappears
(d) Monochromatic pattern
Answer: (c) Disappears
Question 23. Which of the following does not show any interference pattern?
(a) Soap bubble
(b) Excessively thin film
(c) A thick film
(d) Wedge Shaped film
Answer: (b) Excessively thin film
Question 24. Interference occurs in:
(a) longitudinal waves only
(b) transverse waves only
(c) electromagnetic waves only
(d) all above waves
Answer: (d) all above waves
Question 25. The main principle used in Interference is ________
(a) Heisenberg’s Uncertainty Principle
(b) Superposition Principle
(c) Quantum Mechanics
(d) Fermi Principle
Answer: (b) Superposition Principle
Question 26. If instead of monochromatic light white light is used for interference of light, what would be the change in the observation?
(a) The pattern will not be visible
(b) The shape of the pattern will change from hyperbolic to circular
(c) Colored fringes will be observed with a white bright fringe at the center
(d) The bright and dark fringes will change position
Answer: (c) Colored fringes will be observed with a white bright fringe at the center
Question 27. The shape of the pattern depends on the ______
(a) Distance between the slits
(b) Distance between the slits and the screen
(c) Wavelength of light
(d) Shape of the slit
Answer: (d) Shape of the slit
Question 28. A thin sheet of refractive index 1.5 and thickness 1 cm is placed in the path of light. What is the path difference observed?
(a) 0.003 m
(b) 0.004 m
(c) 0.005 m
(d) 0.006 m
Answer: (c) 0.005 m
Question 29. According to stoke’s law, the expression for maxima is: 2μtcosr = ________
(a) nλ
(b) 2nλ
(c) (2n + 1) λ/2
(d) (n + 1) λ/2
Answer: (c) (2n + 1) λ/2
Question 30. Two waves having the intensities in the ratio of 9:1 produce interference. The ratio of maximum to minimum intensity is equal to:
(a) 10 : 8
(b) 9 : 1
(c) 4 : 1
(d) 2 : 1
Answer: (c) 4 : 1
Question 31. The interference pattern of soap bubble changes continuously.
(a) True
(b) False
Answer: (a) True
Question 32. When a thin plate of refractive index 1.5 is placed in the path of one of interfering beams of Michaelson Interferometer, a shift of 30 fringes is observed. If the thickness of plate is 0.018 mm, the wavelength of the used light is ____
(a) 4000 Å
(b) 5000 Å
(c) 6000 Å
(d) 7000 Å
Answer: (c) 6000 Å
Question 33. In a Fresnel’s bipriment, the central fringe is:
(a) bright
(b) dark
(c) first bright and then dark
(d) first dark and then bright
Answer: (a) bright
Question 34. A thin layer of colorless oil is spread over water in a container (μ = 1.4). If the light of wavelength 640 nm is absent in the reflected light, what is the minimum thickness of oil layer?
(a) 179.6 nm
(b) 198.3 nm
(c) 207.6 nm
(d) 214.3 nm
Answer: (d) 214.3 nm
Question 35. The phenomenon of interference is used to prove that light is:
(a) longitudinal
(b) transverse
(c) stationary wave
(d) quantized
Answer: (d) quantized
Question 36. In Newton’s ring experiment, the diameter of the 10th ring changes from 1.40 to 1.23 cm when a liquid is introduced between the lens and glass plate. What is the refractive index of the liquid?
(a) 1.05
(b) 1.15
(c) 1.25
(d) 1.35
Answer: (c) 1.25
Question 37. What would be the resultant intensity at a point of constructive interference, if there are two identical coherent waves of intensity I’ producing an interference pattern?
(a) 4 I’
(b) 0
(c) I’
(d) 2 I’
Answer: (a) 4 I’
Question 38. When light suffers reflection at the interface between water and glass, the change of phase in the reflected wave is
(a) zero
(b) π
(c) π/2
(d) 2π
Answer: (b) π
Question 39. The sources of light are said to be coherent if the waves produced by them have the same:
(a) wavelength
(b) amplitude
(c) wavelength and a constant phase difference
(d) amplitude and the same wavelength
Answer: (c) wavelength and a constant phase difference
Question 40. In interference with two coherent sources, the fringe width varies:
(a) directly as wavelength
(b) inversely as wavelength
(c) directly as the separation between slits
(d) inversely as the distance between the slits and screen
Answer: (a) directly as wavelength
Question 41. In Young’s double slit experiment if the slit widths are in the ratio 1 : 9, the ratio of the intensity at minima to that at maxima will be:
(a) 1
(b) 1/9
(c) 1/4
(d) 1/3
Answer: (c) 1/4
Question 42. In Youngs experiment, when the distance between slit and screen is doubled, while separation of slit is halved, then fringe width will be:
–: End of Interference of Light MCQs Type Questions Class 12 :–
-: also visit :-
- ISC Sem-2 Question Bank Class-12
- Sem-2 ISC Specimen Paper for Class-12
- ISC Class-12 Textbook Solutions ,Syllabus, Solved Paper
- Previous Year Question Paper for ISC Class-12
Please share with your ISC friends if it is helpful
Thanks
