This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Physics Part Ii > Class 12 Physics (Part Ii) Chapter 10 Wave Optics – Quiz 3 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part Ii) Chapter 10 Wave Optics Quiz 3 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the shape of the wavefront on earth for sunlight? A) Spherical. B) Cylindrical. C) Plane. D) None of these. Show Answer Correct Answer: C) Plane. 2. In order to produce a sustained interference pattern by light waves from multiple sources, which of the following conditions must be met? A) Sources are coherent. B) Sources are monochromatic. C) Both choices above are valid. D) None of the choices are valid. Show Answer Correct Answer: C) Both choices above are valid. 3. What is the value of coherent time if L is the coherent length and c is the velocity of light? A) 1/Lc. B) C/L. C) CL. D) L/c. Show Answer Correct Answer: D) L/c. 4. Coherent sources have same A) Frequency. B) Wavelength. C) Phase. D) All the above. Show Answer Correct Answer: D) All the above. 5. For the Michelson interferometer to work accurately, the two mirrors must be: A) At 45$^\circ$ to each other. B) Perfectly parallel. C) Slightly tilted. D) At 90$^\circ$ to each other. Show Answer Correct Answer: D) At 90$^\circ$ to each other. 6. The dual nature of light is exhibited by ..... A) Photoelectric effect. B) Refraction and interference. C) Diffraction and reflection. D) Diffraction and photoelectric effect. Show Answer Correct Answer: D) Diffraction and photoelectric effect. 7. In Young's double slit experiment, constructive interference occurs when the path difference between the two waves is: A) An odd multiple of half wavelengths. B) Equal to the distance between the slits. C) A multiple of the wavelength. D) Zero only. Show Answer Correct Answer: C) A multiple of the wavelength. 8. If I$_{0}$ is the intensity of principal maximum in the single slit diffraction pattern, then what will be its intensity when slit width is double A) I$_{0}$. B) I$_{0 }$/2. C) 4I$_{0}$. D) 2I$_{0}$. Show Answer Correct Answer: A) I$_{0}$. 9. The ratio of intensities of two light sources in YDSE is 4:1. The ratio of their amplitudes will be: A) 2:1. B) 1:4. C) 4:1. D) 16:1. Show Answer Correct Answer: A) 2:1. 10. Which of these best describes a key difference in geometry between Fresnel and Fraunhofer diffraction? A) Fresnel requires at least two slits. B) Fraunhofer occurs only in vacuum. C) Fresnel is near-field, Fraunhofer is far-field. D) Fraunhofer uses diverging sources, Fresnel does not. Show Answer Correct Answer: C) Fresnel is near-field, Fraunhofer is far-field. 11. In diffraction pattern A) We get the fringes of same intensities. B) We get all the fringed of same width. C) We get the fringes of different intensities and different width. D) We get fringes of same intensites but different width. Show Answer Correct Answer: C) We get the fringes of different intensities and different width. 12. You observe two very closely-spaced sources of white light through a circular opening using various filters. Which color filter is most likely in resolving the images on your retinas as coming from two distinct sources? A) Yellow. B) Red. C) Green. D) Blue. Show Answer Correct Answer: D) Blue. 13. Which one of the following phenomena is not explain by Huygen's construction of wavefront? A) Diffraction. B) Refraction. C) Reflection. D) Origin of spectra. Show Answer Correct Answer: D) Origin of spectra. 14. The colour of bright fringe nearest to central achromatic fringe in the interference pattern with white light will be A) Yellow. B) Red. C) Violet. D) Green. Show Answer Correct Answer: B) Red. 15. For the greatest amount of diffraction to occur when a wave reaches a barrier, the barrier must be A) Largerthan the wavelength. B) Atleast twice the size of the wavelength. C) Thesame size or smaller than the wavelength. D) Theexact same size as the wavelength. Show Answer Correct Answer: C) Thesame size or smaller than the wavelength. 16. As a result of interference of two coherent sources of light, energy is ..... A) Increased. B) Redistributed and the distribution does not vary with time. C) Decreased. D) Redistributed and the distribution changes with time. Show Answer Correct Answer: B) Redistributed and the distribution does not vary with time. 17. For destructive interference, A) Crest of one wave coincides with trough of other. B) Trough of one wave coincides with trough of the other. C) Crest of one wave coincides with crest of other. D) Formation of crest and trough is not necessary. Show Answer Correct Answer: A) Crest of one wave coincides with trough of other. 18. Wavelength of an incident light when it is incident normally on a diffraction grating having 3000 lines per centimeter angular separation is 10$^\circ$ is A) 580 nm. B) 600 nm. C) 500 nm. D) 650 nm. Show Answer Correct Answer: A) 580 nm. 19. In young's double slit experiment A) All fringes have same thickness. B) Central bright is of double width. C) Central fringe is intense. D) Thickness of fringes decreases gradually. Show Answer Correct Answer: A) All fringes have same thickness. 20. What is the primary cause of the colors seen in a soap bubble? A) Refraction of light. B) Reflection of light. C) Interference of light. D) Diffraction of light. Show Answer Correct Answer: C) Interference of light. 21. When waves come together to for a larger wave for a brief period of time A) Additive waves. B) Destructive waves. C) Constructive waves. D) Subtractive waves. Show Answer Correct Answer: C) Constructive waves. 22. Two coherent monochromatic light beams of intensities I and 4I superimpose. The maximum and minimum possible intensities in the resulting beam are A) 5I and I. B) 5I and 3I. C) 3I and I. D) 9I and I. Show Answer Correct Answer: D) 9I and I. 23. In which type of diffraction, diffracted light is collected by a lens in a telescope A) Fresnel's. B) Fraunhoffer's. C) Both. D) None. Show Answer Correct Answer: B) Fraunhoffer's. 24. Glass plate of refractive index 1.732 is to be used as a polariser, its polarising angle is A) 45$^\circ$. B) 60$^\circ$. C) 90$^\circ$. D) 30$^\circ$. Show Answer Correct Answer: B) 60$^\circ$. 25. In YDSE uses a monochromatic source. The shape of the interference fringes formed on the screen is A) Parabola. B) Circle. C) Hyperbola. D) Straight line. Show Answer Correct Answer: C) Hyperbola. 26. In the Nicol Prism experiment, the calcite crystal length is x times its breadth. What is x? A) 1/2. B) 1/3. C) 3. D) 2. Show Answer Correct Answer: C) 3. 27. Soap bubble appears coloured due to the phenomenon of ..... A) Diffraction. B) Reflection. C) Dispersion. D) Interference. Show Answer Correct Answer: D) Interference. 28. Diffraction of light is the A) Superposition of waves emitted from coherent sources. B) Bending of light when it travels from one medium to another medium. C) Splitting of a white ray of light in seven colour rays. D) Bending of light around the corners of a very thin aperature. Show Answer Correct Answer: D) Bending of light around the corners of a very thin aperature. 29. Which parameter changes while a ray of light propagates from one medium to another? A) Velocity. B) Wave length. C) Frequency. D) Both a and b. Show Answer Correct Answer: D) Both a and b. 30. What will be the angle of diffracting for the first minimum due to Fraunhoffer diffraction with sources of light of wave length 550 nm and slit of width 0.55 mm A) 0.001 rad. B) 0.01 rad. C) 1 rad. D) 0.1 rad. Show Answer Correct Answer: A) 0.001 rad. 31. A wavefront is defined as a surface of ..... A) Variable Phase. B) Constant Phase. C) All the above. D) None of the above. Show Answer Correct Answer: B) Constant Phase. 32. What is the role of the mirrors in a Michelson interferometer? A) To change the polarization of the light. B) To focus the light onto a detector. C) To reflect the light beams back to the beam splitter. D) To absorb excess light. Show Answer Correct Answer: C) To reflect the light beams back to the beam splitter. 33. Diffraction aspect is easier to notice in case of the sound waves then in case of the light waves because sound waves A) Have longer wavelength. B) Longitudinal wave. C) Shorter wavelength. D) Transverse waves. Show Answer Correct Answer: A) Have longer wavelength. 34. What is the angle made by the ray of light on the wave front? A) 90. B) 0. C) 45. D) 60. Show Answer Correct Answer: A) 90. 35. Which of the following is conserved when light waves interfere ..... A) Momentum. B) Energy. C) Intensity. D) Amplitude. Show Answer Correct Answer: B) Energy. 36. Two wave having intensity in the ratio 25:4 produce interference . The ratio of maximum to the minimum intensity will be A) 2:5. B) 9:49. C) 5:2. D) 49:9. Show Answer Correct Answer: D) 49:9. 37. The alternate bright and dark bands of light due to interference are called as interference fringes. A) False. B) True. C) None of the above. D) None of the above. Show Answer Correct Answer: B) True. 38. Two tunning forks have frequencies 412 Hz and 409 He respectively. Calculate the period of the beat. A) 1.03 s. B) 1.33 s. C) 0.13 s. D) 0.33 s. Show Answer Correct Answer: D) 0.33 s. 39. If a plane wavefront is incident on a concave mirror, then the emergent wavefront will be ..... of the mirror as its centre. A) Conical with focus. B) Conical with centre of the curvature of the surface. C) Spherical with focus. D) Spherical with centre of the curvature of the surface. Show Answer Correct Answer: C) Spherical with focus. 40. If it takes a waves 2.0 s to travel a distance of 10 meters, what is the wave speed? A) 12 m/s. B) 0.2 m/s. C) 5 m/s. D) 20 m/s. Show Answer Correct Answer: C) 5 m/s. 41. Wavelength of light of frequency 100Hz A) 5 x 10$^{6}$ m. B) 3 x 10$^{6}$ m. C) 2 x 10$^{6}$ m. D) 4 x 10$^{6}$ m. Show Answer Correct Answer: B) 3 x 10$^{6}$ m. 42. Huygen's originally thought that for the propagation of light waves wavefront is required. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 43. Ratio of intensities of two waves are given by 4:1. Then the ratio of amplitudes of the two wave is A) 2:1. B) 4:1. C) 1:2. D) 1:4. Show Answer Correct Answer: A) 2:1. 44. Huygens' principle fails to explain which of the following? A) Diffraction. B) Polarization. C) Interference. D) Refraction. Show Answer Correct Answer: B) Polarization. 45. What do we mean when we say that two lightrays striking a screen are in phase with each other? A) When the electric field due to one is a maximum, the electric field due to the other is also a maximum, and this relation is maintained as time passes. B) They are traveling at the same speed. C) They have the same wavelength. D) They alternately reinforce and cancel each other. Show Answer Correct Answer: A) When the electric field due to one is a maximum, the electric field due to the other is also a maximum, and this relation is maintained as time passes. 46. The Michelson interferometer works based on which optical principle? A) Refraction. B) Interference. C) Reflection. D) Diffraction. Show Answer Correct Answer: B) Interference. 47. The spherical wave front is received A) Near the Sun. B) Near a lighting tube-light. C) When the light wave is coming from Sun to Earth. D) All of the above. Show Answer Correct Answer: A) Near the Sun. 48. In Young's double slit experiment, which laser would result in the closest together bright spots? A) Violet (410 nm). B) Blue (450 nm). C) Red (650 nm). D) Green (550 nm). Show Answer Correct Answer: A) Violet (410 nm). 49. The colours on the soap bubble is due to A) Diffraction. B) Reflection. C) Interference. D) Polarisation. Show Answer Correct Answer: C) Interference. 50. A beam of light which consists of two different wavelength $\lambda_1$ $\lambda_2$ $\lambda_1>\lambda_2$ $\lambda_1$ $\lambda_2$ $\frac{\lambda_1}{\lambda_2}$ A) 2.0. B) 3.0. C) 2.5. D) 1.5. Show Answer Correct Answer: D) 1.5. 51. The width of diffraction band varies A) Inversely as the wavelength. B) Directly as the width of the slit. C) Directly as the distance between the slit and the screen. D) Inversely as the size of the source from which the slit is illuminated. Show Answer Correct Answer: C) Directly as the distance between the slit and the screen. 52. What happens, if the monochromatic light used in Young's double slit experiment is replaced by white light? A) No fringes are observed. B) All bright fringes become while. C) All bright fringes have colour between violet and red. D) Only the central fringe is white and all other fringes are coloured. Show Answer Correct Answer: D) Only the central fringe is white and all other fringes are coloured. 53. In double refraction, two refracted rays are produced, called as O-ray and E-ray. Which of the following statements is TRUE A) Only O-ray is polarised. B) Only E-ray is polarised. C) Both O-ray and E-ray are polarised. D) Neither E-ray nor O-ray are polarised. Show Answer Correct Answer: C) Both O-ray and E-ray are polarised. 54. Phenomenon that establishes transvers nature of light is A) Polarization. B) Diffraction. C) Photoelectric effect. D) Interference. Show Answer Correct Answer: A) Polarization. 55. Which of the following does not affect the interference pattern in a Michelson interferometer? A) Size of the beam splitter. B) Refractive index of medium in one arm. C) Wavelength of light. D) Mirror displacement. Show Answer Correct Answer: A) Size of the beam splitter. 56. Which of the following sources is most coherent? A) Sunlight. B) Incandescent bulb. C) LED. D) Laser. Show Answer Correct Answer: D) Laser. 57. Sound wave do not exhibit ..... A) Reflection. B) Diffraction. C) Interference. D) Polarisation. Show Answer Correct Answer: D) Polarisation. 58. In Young's double-slit experiment, the intensity is I at a point, where the path difference is $\lambda$/6 ($\lambda$-wavelength of light used). If I$_{0}$ denotes the maximum intensity then I/I$_{0}$ is equal to A) 1/2. B) $\frac{1}{\sqrt{2}}$. C) $\sqrt{\frac{3}{2}}$. D) 3/4. Show Answer Correct Answer: D) 3/4. 59. Two coherent sources of light can be obtained from A) Two different lamps. B) Two different lamps of different colours. C) Two different lamps of the same colour. D) None of these. Show Answer Correct Answer: D) None of these. 60. In Fraunhofer diffraction from a single slit, increasing the slit width will: A) Increase the fringe width. B) Decrease the fringe width. C) Eliminate diffraction entirely. D) Cause fringes to shift randomly. Show Answer Correct Answer: B) Decrease the fringe width. ← PreviousNext →Related QuizzesScience QuizzesClass 12 QuizzesClass 12 Physics (Part Ii) Chapter 10 Wave Optics Quiz 1Class 12 Physics (Part Ii) Chapter 10 Wave Optics Quiz 2Class 12 Physics (Part Ii) Chapter 10 Wave Optics Quiz 4Class 12 Physics (Part Ii) Chapter 10 Wave Optics Quiz 5Class 12 Physics (Part Ii) Chapter 11 Dual Nature Of Radiation And Matter QuizClass 12 Physics (Part Ii) Chapter 12 Atoms QuizClass 12 Physics (Part Ii) Chapter 13 Nuclei QuizClass 12 Physics (Part Ii) Chapter 14 Semiconductor Electronics Materials Quiz 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books