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 4 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part Ii) Chapter 10 Wave Optics Quiz 4 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The shape of wave front from a distant souce of light will be A) Plane. B) Cylindrical. C) Spherical. D) Elliptical. Show Answer Correct Answer: A) Plane. 2. Which type of diffraction typically shows fewer but sharper fringes? A) Fresnel diffraction. B) Fraunhofer diffraction. C) Both show same pattern. D) Neither. Show Answer Correct Answer: B) Fraunhofer diffraction. 3. Coherent sources are those sources for which A) Phase difference remain constant. B) Frequency remains constant. C) Both phase difference and frequency remains constant. D) None of these. Show Answer Correct Answer: C) Both phase difference and frequency remains constant. 4. A point source of light is placed in front of a plane mirror. A) All the reflected rays meet at a point when produced backward. B) Only the reflected rays close to the normal meet at a point when produced backward. C) Only the reflected rays making a small angle with the mirror, meet at a point when produced backward. D) Light of different colours make different images. Show Answer Correct Answer: A) All the reflected rays meet at a point when produced backward. 5. Doubly refracting calcite crystal is placed over an ink dot. On seeing through the crystal, one observes. A) Both dots rotating about a comman axis. B) Two stationary dots. C) One dot rotating about the other. D) A single dot. Show Answer Correct Answer: C) One dot rotating about the other. 6. Figure 10.2 shows a standard two slit arrangement with slits $S_{1, }S_{2, }P_1P_2$ $P_2$ $P_2$ $S_{3, }S_4$ A) There would be no interference pattern on thesecond screen but it would be lighted. B) The second screen would be totally dark. C) There would be a single bright point on the second screen. D) There would be a regular two slit pattern on the second screen. Show Answer Correct Answer: D) There would be a regular two slit pattern on the second screen. 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. Show Answer Correct Answer: B) Conservation of energy. 8. Which of the following devices uses the wave nature of light to separate different wavelengths? A) Convex lens. B) Optical fiber. C) Diffraction grating. D) Concave mirror. Show Answer Correct Answer: C) Diffraction grating. 9. Electromagnetic waves have A) Electric field only. B) Magnetic field only. C) Both electric and magnetic field. D) None of the above. Show Answer Correct Answer: C) Both electric and magnetic field. 10. In a Young's double-slit interference apparatus, the distance from the slits to the screen is doubled. The distance between adjacent light and dark fringes changes by a factor of A) 1/4. B) 1/2. C) 2. D) 4. Show Answer Correct Answer: D) 4. 11. Secondary wave principle given by A) Huygen. B) Newton. C) Melus. D) Brewster. Show Answer Correct Answer: A) Huygen. 12. The substance the wave travels through (solid, liquid, gas) A) Crest. B) Seismic. C) Trough. D) Medium. Show Answer Correct Answer: D) Medium. 13. For Young's double slit interference distance of $n^{th}$ A) $\frac{n\lambda d}{D}$. B) $\left(n+\frac{1}{2}\right)\\frac{\lambda D}{d}$. C) $\left(n+\frac{1}{2}\right)\\frac{\lambda d}{D}$. D) $\frac{n\lambda D}{d}$. Show Answer Correct Answer: D) $\frac{n\lambda D}{d}$. 14. The ratio of the amplitude of the two sources producing interference 3:5, the ratio of intensities at maxima and minima is A) 5:3. B) 16:1. C) 25:9. D) 25:6. Show Answer Correct Answer: B) 16:1. 15. A diffraction grating with 2400 lines per centimetre is used to produce a diffraction pattern that is recorded by a detector. The first-order fringe is 8.94 cm from central fringe. If the distance between the grating and the detector is 0.625 m, what is the wavelength of the electromagnetic wave used? A) 295 nm. B) 1180 nm. C) 590 nm. D) 1190 nm. Show Answer Correct Answer: C) 590 nm. 16. When exposed to sunlight, thin films of oil on water often exhibit brilliant colors due to the phenomenon of A) Interference. B) Polarisation. C) Dispersion. D) Diffraction. Show Answer Correct Answer: A) Interference. 17. The nature of the wavefront for a point source of light is ..... A) Spherical wanefront. B) Plane wavefront. C) All the above. D) None of the above. Show Answer Correct Answer: A) Spherical wanefront. 18. According to Brewster's law, at polarising angle, the reflected and refracted rays are A) Parallel to each other. B) Antiparallel to each other. C) Perpendicular to each other. D) At 40$^\circ$ to each other. Show Answer Correct Answer: C) Perpendicular to each other. 19. A repeating and periodic disturbance that travels from one location to another carrying energy A) Trough. B) Energy. C) Wave. D) Amplitude. Show Answer Correct Answer: C) Wave. 20. When the wavelength and wave speed are quadrupled, then the wave's frequency will be ..... A) Quadrupled. B) Constant. C) Doubled. D) Halved. Show Answer Correct Answer: B) Constant. 21. Polarization of light is best described by A) The bouncing back of light form mirror. B) Restricting component of light in a particular direction. C) The splitting of white light into seven colours. D) Change of direction of light when it passes form one transparent medium to another. Show Answer Correct Answer: B) Restricting component of light in a particular direction. 22. A wavefront is defined as a surface of ..... phase. A) Decreasing. B) Constant. C) Increasing. D) Time variable. Show Answer Correct Answer: B) Constant. 23. Two slits in Young's double slit experiment have widths in the ratio 81:1. The ratio of the amplitudes of light waves is A) 3:2. B) 9:1. C) 6:1. D) ) 3:1(b) (c) (d) 6:1. Show Answer Correct Answer: B) 9:1. 24. If a wave is traveling at 15 m/s and has a frequency of 5.0 Hz, what is its wavelength? A) 0.33 m. B) 20 m. C) 75 m. D) 3 m. Show Answer Correct Answer: D) 3 m. 25. A star appears to be white according to its spectral composition, but it appears blue when observed through a telescope. What is the best explanation for this phenomenon? A) A The object is moving toward Earth. B) B The object is moving away from Earth. C) C The object is moving parallel to Earth. D) D all of the above. Show Answer Correct Answer: A) A The object is moving toward Earth. 26. Which of these is the correct expression for Malus law for polarization of light A) $I=I_o\cos^2\\frac{\theta}{2}$. B) $I=I_o^2\cos\theta$. C) $I=I_o\cos^2\theta$. D) $I=I_o\cos\theta$. Show Answer Correct Answer: C) $I=I_o\cos^2\theta$. 27. In YDSE is carried out green, red, blue light one color at atime .The fringe width recorded are $\beta$$_{G}$ $\beta$$_{R}$ $\beta$$_{B}$ respectively ; Then A) $\beta$$_{B }$<$_{ }$$\beta$$_{G }$<$_{ }$$\beta$$_{R}$. B) $\beta$$_{G}$ < $\beta$$_{R}$ < $\beta$$_{B}$. C) $\beta$$_{R}$ < $\beta$$_{B}$<$_{ }$$\beta$$_{G }$. D) $\beta$$_{R }$< $_{ }$$\beta$$_{G}$ < $\beta$$_{B}$. Show Answer Correct Answer: A) $\beta$$_{B }$<$_{ }$$\beta$$_{G }$<$_{ }$$\beta$$_{R}$. 28. Constructive interference of light results in dark fringe A) False. B) True. C) All the above. D) None of the above. Show Answer Correct Answer: A) False. 29. The ratio of the widths of two slits in Young's double slit experiment is 4:1. Evaluate the ratio of intensities at maxima and minima in the interference pattern. A) 1:4. B) 3:1. C) 1:1. D) 9:1. Show Answer Correct Answer: D) 9:1. 30. A sound wave differs from a light wave because a sound wave ..... A) Is produced by an oscillating object and a light wave is not. B) Is not capable of traveling through a vacuum. C) Is not capable of diffracting and a light wave is. D) Is capable of existing with a variety of frequencies and a light wave has a single frequency. Show Answer Correct Answer: B) Is not capable of traveling through a vacuum. 31. If on rotating an analyser there no variation in the intensity of light then the light is A) Plane polarized. B) Unpolarized. C) Partially polarized. D) Extra ordinary. Show Answer Correct Answer: B) Unpolarized. 32. Visible light wavelengths range from 400 nm-700 nm. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 33. Light waves travelling through air strike the surface water at an angle. Which of the following statements is correct? A) The light speed, frequency and wavelength all stay the same. B) The light speed, frequency and wavelength all change. C) The light speed and frequency change, but the wavelength stays the same. D) The light wavelength and speed change but frequency stays the same. Show Answer Correct Answer: D) The light wavelength and speed change but frequency stays the same. 34. In Young's double slit experiment, the two coherent sources have different intensities. If the ratio of maximum intensity to the minimum intensity in the interference pattern produced is25:1. What was the ratio of intensities of the two A) 5:1. B) 9:4. C) 25:1. D) 3:2. Show Answer Correct Answer: B) 9:4. 35. The term coherence relates to ..... A) The amplitude of two waves. B) The phase relationship between two waves. C) The diffraction of two waves. D) The polarization state of two waves. Show Answer Correct Answer: B) The phase relationship between two waves. 36. For diffraction of light condition of getting secondary minima is A) $x=\frac{\left(2n+1\right)\lambda}{2}$. B) $x=\left(2n+1\right)\lambda$. C) $x=n\lambda$. D) None of these. Show Answer Correct Answer: C) $x=n\lambda$. 37. In vacuum optical path is A) Infinite. B) Equal to actual path travelled. C) Less than actual path travelled. D) Greater than actual path travelled. Show Answer Correct Answer: B) Equal to actual path travelled. 38. The phenomena which is not explained by Huygen's construction of wavefront A) Refraction. B) Origin of spectra. C) Diffraction. D) Reflection. Show Answer Correct Answer: B) Origin of spectra. 39. If the intensity of a monochromatic ray of light is increased while the ray is incident on a pair of narrow slits, the spacing between maxima in the diffraction pattern will be ..... A) The same. B) Increased or decreased, depending on frequency. C) Increased. D) Decreased. Show Answer Correct Answer: A) The same. 40. Resolving power of microscope depends upon A) Wavelength of light used (directly proportional). B) Frequency of light used. C) Wavelength of light used (inversely proportional). D) Focal length of objective. Show Answer Correct Answer: C) Wavelength of light used (inversely proportional). 41. Which condition is essential for superposition to produce observable interference patterns? A) Waves must be polarized. B) Waves must have different velocities. C) Waves must be coherent. D) Waves must travel in opposite directions. Show Answer Correct Answer: C) Waves must be coherent. 42. Approximately how much light is blocked by two polarizing filters that are perpendicular to each other? A) 50%. B) 75%. C) 0%. D) 100%. Show Answer Correct Answer: D) 100%. 43. Two wave are said to be a coherent, if they have A) Same frequency but different amplitude. B) Same phase & different amplitude. C) Difference frequency, phase & amplitude. D) Same frequency, phase & amplitude. Show Answer Correct Answer: D) Same frequency, phase & amplitude. 44. Intensity of secondary maxima in diffraction has A) Same intensity as central maxima. B) Less intensity than central maxima. C) More intensity than central maxima. D) None of these. Show Answer Correct Answer: C) More intensity than central maxima. 45. Huygens wave theory couldn't explain A) Photoelectric effect. B) Interference. C) Polarisation. D) Diffraction. Show Answer Correct Answer: A) Photoelectric effect. 46. In YDSE the separation between the slits and the distance between slits and screen both are halved. What will be effect on the interference pattern observed? A) Fringe width will be 4 times. B) No effect. C) Fringe width will be 1/4 times. D) Fringe width will be doubled. Show Answer Correct Answer: B) No effect. 47. The phenomenon of beats is due to A) Reflection. B) Superposition of coherent waves. C) Superposition of incoherent waves. D) Refraction. Show Answer Correct Answer: B) Superposition of coherent waves. 48. .In Young's double-slit experiment, if there is no initial phase difference between the light from two slits, a point on the screen corresponding to the fifth minimum has path difference A) 9 $\lambda$/2. B) 11$\lambda$/2. C) 5 $\lambda$/2. D) 57$\lambda$/. Show Answer Correct Answer: A) 9 $\lambda$/2. 49. Condition for getting bright fringe in YDSE is A) $x=\left(n+1\right)\lambda$. B) $x=\frac{\left(2n+1\right)\lambda}{2}$. C) $x=\frac{\left(2n-1\right)\lambda}{2}$. D) $x=n\lambda$. Show Answer Correct Answer: D) $x=n\lambda$. 50. Thin film of kerosene on water surface appear coloured due to A) Scattering. B) Interference. C) Refraction. D) Dispersion. Show Answer Correct Answer: B) Interference. 51. What is the primary reason for using a diffraction grating in optical experiments? A) To focus light. B) To polarize light. C) To reflect light. D) To separate different wavelengths. Show Answer Correct Answer: D) To separate different wavelengths. 52. The working of Nicole prism is based on the phenomenon of ..... A) Double Refraction. B) Diffraction. C) Refraction. D) Reflection. Show Answer Correct Answer: A) Double Refraction. 53. Wavefront means ..... A) All particles in it have same phase. B) All particles have opposite phase of vibrations. C) All particles have opposite phase of vibrations. D) None of these. Show Answer Correct Answer: A) All particles in it have same phase. 54. When the light falls normally on a small-angled wedge film then the fringe width $\beta$ A) $\beta=\frac{\lambda}{2\mu\cos\alpha}$. B) $\beta=\frac{\lambda}{2\\tan\alpha\sqrt{\mu^2-\sin^2i}}$. C) $\beta=\frac{\lambda}{\mu\alpha}$. D) $\beta=\frac{\lambda}{2\mu\alpha}$. Show Answer Correct Answer: D) $\beta=\frac{\lambda}{2\mu\alpha}$. 55. Which one of the following phenomena is not explained by Huygen's construction of wavefront ..... A) Reflection. B) Diffraction. C) Origin of spectra. D) Refraction. Show Answer Correct Answer: C) Origin of spectra. 56. Consider the diffraction pattern for a small pinhole. as the size of hole is increased then the central bright ..... A) The size decreases. B) No change. C) The size increases. D) No effect. Show Answer Correct Answer: A) The size decreases. 57. When Sunlight strikes air molecules ordust particles in the atmosphere, it changesits direction. This is called ..... A) Interference. B) Polarization. C) Dispersion. D) Scattering. Show Answer Correct Answer: D) Scattering. 58. If the 2nd order maximum for a double-slit experiment occurs at an angle of 45.0$^{o}$, what is the relationship between the wavelength and the distance between the slits? A) D = 2.83 $\lambda$. B) D = 4.00 $\lambda$. C) D = 2.00 $\lambda$. D) D = 1.41 $\lambda$. Show Answer Correct Answer: A) D = 2.83 $\lambda$. 59. On passing a plane wavefront through a concave lens, we get a A) Plane wavefront. B) Spherical wavefront. C) Parabolic wavefront. D) Cylindrical wavefront. Show Answer Correct Answer: B) Spherical wavefront. 60. According to the above given fig., identify the correct expression for Snell's law. A) A) n1 sin i = n2 sin r. B) B) n2 sin i = n1 sin r. C) C) n21 = sin r/ sin i. D) None of these. Show Answer Correct Answer: A) A) n1 sin i = n2 sin r. ← 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 3Class 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