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 5 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part Ii) Chapter 10 Wave Optics Quiz 5 (51 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Two waves interfere constructively when their optical path lengths ..... A) Are equal or differ by integral multiples of wavelength. B) Are unequal. C) Are equal or differ by odd integral multiples of wavelength. D) Are equal or differ by even integral multiples of wavelength. Show Answer Correct Answer: A) Are equal or differ by integral multiples of wavelength. 2. A single slit of width 0.20 mm is illuminated with light of wavelength 500 nm. The observing screen is placed 80 cm from the slit. The width of the central bright fringe will be ..... A) 5 mm. B) 2 mm. C) 1 mm. D) 4 mm. Show Answer Correct Answer: D) 4 mm. 3. The index of refraction of air is approximately ..... A) 0.5. B) 2.0. C) 1.0. D) 1.5. Show Answer Correct Answer: C) 1.0. 4. If the speed of a wave remains constant, and the wavelength is doubled, then the frequency will be ..... A) Halved. B) Quadrupled. C) Remains constant. D) Doubled. Show Answer Correct Answer: A) Halved. 5. The energy of the wave travels in a direction ..... to the wavefront. A) Similarly. B) Oppositely. C) Perpendicularly. D) None. Show Answer Correct Answer: C) Perpendicularly. 6. In a double-slit interference experiment you areasked to use laser light of different wavelengths anddetermine the separation between adjacent maxima.You observe that this separation is greatest when youilluminate the double slit with ..... A) Green light. B) Yellow light. C) Blue light. D) Red light. Show Answer Correct Answer: D) Red light. 7. Newton's Rings are produced by A) Interference of light. B) Polarization of light. C) Refraction. D) Reflection. Show Answer Correct Answer: A) Interference of light. 8. What electromagnetic wave travels the fastest? A) Microwave. B) Ultraviolet. C) Xray. D) All travel at the speed of light 'c'. Show Answer Correct Answer: D) All travel at the speed of light 'c'. 9. In youngs double slit experiment if entire apparatus is immersed in water the fridge width would A) Decrease. B) Increase. C) Not change. D) None of the above. Show Answer Correct Answer: A) Decrease. 10. A binary star is observed with a telescope. A coloured filter is used to maximise the resolution. (A filter of a given colour transmits only that colour of light). What colour filter would give the greatest increase in the resolution? A) Blue. B) Green. C) Yellow. D) Red. Show Answer Correct Answer: A) Blue. 11. Property of light wave does not change on change in medium A) Amplitude. B) Speed. C) Wavelength. D) Frequency. Show Answer Correct Answer: D) Frequency. 12. In Fraunhofer diffraction, the source and screen are: A) Effectively at infinity or collimated using lenses. B) Placed inside a vacuum chamber. C) Very close to the slit. D) At a finite distance from the slit. Show Answer Correct Answer: A) Effectively at infinity or collimated using lenses. 13. If plane mirror is used in place of glass plate in Newton's Ring experiment- A) No fringes are seen. B) Only bright fringes are seen. C) Only dark fringes are seen. D) Multicolour fringes are seen. Show Answer Correct Answer: A) No fringes are seen. 14. In Young's double slit experiment the separation between the slits is halved and distance between slits and screen is doubled. The width is A) Unchanged. B) Halved. C) Doubled. D) Quadrupled. Show Answer Correct Answer: D) Quadrupled. 15. Two light sources are said to be coherent if they A) Are of the same frequency. B) Are of the same frequency, and maintain a constant phase difference. C) Are of the same amplitude, and maintain a constant phase difference. D) Are of the same frequency and amplitude. Show Answer Correct Answer: B) Are of the same frequency, and maintain a constant phase difference. 16. The intensity of light issuing out of two slits in young's experiment is in ratio 1:4. The intensity of the minimum to the maximum will be in the ratio A) 1:2. B) 1:4. C) 1:9. D) None of the above. Show Answer Correct Answer: B) 1:4. 17. A laboratory experiment produces a double-slit interference pattern on a screen. If the screen is moved farther away from the slits, the fringes will be A) Closer together. B) In the same positions. C) Further Apart. D) Fuzzy and out of focus. Show Answer Correct Answer: C) Further Apart. 18. Velocity= 600 m/sWavelength= 2.0mFrequency= ..... A) 300 hertz. B) .0033 hertz. C) 3000 hertz. D) None of the above. Show Answer Correct Answer: A) 300 hertz. 19. Which of the following phenomena cannot be explained by the wave theory of light? A) Interference. B) Photoelectric effect. C) Diffraction. D) Polarization. Show Answer Correct Answer: B) Photoelectric effect. 20. In a Young's double slit experiment, the separation between the slits is 0.1 mm, the wavelength of light used is 600 nm and the interference pattern is observed on a screen 1m away. Find the separation between bright fringes. A) (b) 6.0 mm. B) D) 60cm. C) (a) 6.6 mm. D) (c) 6 m. Show Answer Correct Answer: A) (b) 6.0 mm. 21. A student holds a laser and diffraction grating such that they are projecting a series of bright and dark fringes onto the whiteboard. As the student walks toward the board, the bright spots ..... A) Become closer together. B) Moves farther apart. C) Maintain the same spacing. D) None of the above. Show Answer Correct Answer: A) Become closer together. 22. In a double-slit experiment, what happens to the interference pattern if the light source is changed to a monochromatic source? A) The pattern becomes more distinct. B) The pattern disappears. C) The pattern remains unchanged. D) The pattern becomes less distinct. Show Answer Correct Answer: A) The pattern becomes more distinct. 23. A wave front is surface of constant ..... A) Phase. B) Amplitude. C) Wavelength. D) Frequency. Show Answer Correct Answer: A) Phase. 24. The number of cycles occurring in a certain amount of time in a certain wave is defined as a wave's ..... A) Amplitude. B) Period. C) Wavelength. D) Frequency. Show Answer Correct Answer: D) Frequency. 25. Destructive interference results when a trough meets the trough of another wave. A) False. B) True. C) All the above. D) None of the above. Show Answer Correct Answer: B) True. 26. In Young's double-slit experiment, if the separation between the slits is doubled, the fringe width: A) Doubles. B) Becomes four times. C) Remains the same. D) Becomes half. Show Answer Correct Answer: D) Becomes half. 27. In YDSE two slits are made 5 mm apart and the screen is placed 2 m away. What is the fringe separation when light of wavelength 500 nm is used A) 0.002 mm. B) 0.02 mm. C) 2 mm. D) 0.2 mm. Show Answer Correct Answer: D) 0.2 mm. 28. Relation between phase difference and path difference is A) $x=\frac{\lambda}{2\pi}\phi$. B) $x=\frac{2\pi}{\lambda}\phi$. C) $x=\frac{2\pi\lambda}{\phi}$. D) $x=\frac{\phi}{2\pi\lambda}$. Show Answer Correct Answer: A) $x=\frac{\lambda}{2\pi}\phi$. 29. What is the velocity of light in alcohol (n = 1.36)? A) 3 x 10$^{8}$ m/s. B) 4.08 x 10$^{8}$ m/s. C) 1.36 x 10$^{8}$ m/s. D) 2.2 x 10$^{8}$ m/s. Show Answer Correct Answer: D) 2.2 x 10$^{8}$ m/s. 30. In a vacuum a particular light source gives off light waves with a measured wavelength of 2.0 X 10$^{-7}$ m. What is the frequency of the light source? A) 6.0 X 10$^{-11}$ Hz. B) Not enough information. C) 1.5 X 10$^{15}$ Hz. D) 6.67 X 10$^{-15}$ Hz. Show Answer Correct Answer: C) 1.5 X 10$^{15}$ Hz. 31. Bright spots on the interference pattern are visible because of: A) Destructive Interference of Light. B) Polarization of Light. C) Constructive Interference of Light. D) Light is always bright. Show Answer Correct Answer: C) Constructive Interference of Light. 32. The phenomenon of diffraction can be understood using A) Huygens principle. B) Fraunhofer. C) Uncertainty principle. D) Fresnel. Show Answer Correct Answer: A) Huygens principle. 33. What will be the angular width of central maxima in Fraunhoffer diffraction when light of wavelength 6000 A$^{o}$ is used and slit width is 12 x 10$^{-5}$ cm A) 2 rad. B) 8 rad. C) 3 rad. D) 1 rad. Show Answer Correct Answer: D) 1 rad. 34. The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 A is of the order of A) 10$^{6}$ rad. B) 10$^{-2}$ rad. C) 10$^{-6}$ rad. D) 10$^{-4}$ rad. Show Answer Correct Answer: C) 10$^{-6}$ rad. 35. Yellow light is used in single slit diffraction experiment with slit width of 0.6 mm . If yellow light is replaced by X-rays, then the observed pattern will reveal: A) More number of fringes. B) That the central maximum is narrower. C) Less number of fringes. D) No diffraction pattern. Show Answer Correct Answer: D) No diffraction pattern. 36. When 2nd secondary maxima is obtained in case of single slit diffraction pattern, the angular position is given by A) 5$\lambda$/2. B) $\lambda$. C) 3$\lambda$/2. D) $\lambda$/2. Show Answer Correct Answer: A) 5$\lambda$/2. 37. When a compact disc is illuminated by a source of white light, colored lines are observed . This is due to A) Dispersion. B) Refraction. C) Interference. D) Diffraction. Show Answer Correct Answer: D) Diffraction. 38. If a wave from one slit of a Young's double-slit experiment set-up arrives at a point on the screen one wavelength behind the wave from the other slit, what is observed at that point? A) Bright fringe. B) Dark fringe. C) Multi-colored fringe. D) Gray fringe, neither bright nor dark. Show Answer Correct Answer: A) Bright fringe. 39. Diffraction and interference of light suggest ..... A) Nature is quantum. B) Nature of light is electro-magnetic. C) Nature of light is transverse. D) Wave nature. Show Answer Correct Answer: D) Wave nature. 40. To demonstrate the phenomenon of interference, we require two sources A) Of the same frequency and having a constant phase difference. B) Of nearly the same frequency. C) Of the same frequency. D) Of different wavelengths. Show Answer Correct Answer: A) Of the same frequency and having a constant phase difference. 41. If the distance between a point source and screen is doubled, then intensity of light on the screen will become ..... A) Half. B) One-fourth. C) Four times. D) Double. Show Answer Correct Answer: B) One-fourth. 42. In diffraction from single slit, the angular width of central maxima does not depend on A) $\lambda$ of light used. B) Width of slit. C) Distance of slits from screen. D) Ratio of the $\lambda$ and slit width. Show Answer Correct Answer: C) Distance of slits from screen. 43. The angular width of the central maxima of the diffraction pattern remains the same A) Diffraction pattern disappears. B) Diffraction pattern becomes broader. C) Diffraction pattern becomes narrower. D) No changes. Show Answer Correct Answer: C) Diffraction pattern becomes narrower. 44. LCD uses the phenomenon of A) Interference. B) Diffraction. C) Polarization. D) Dispersion. Show Answer Correct Answer: C) Polarization. 45. The contrast in the fringes in any interference pattern depends on A) Distance between sources. B) Fringe width. C) Wavelength. D) Intensity ratio of sources. Show Answer Correct Answer: D) Intensity ratio of sources. 46. Which of the following conditions best distinguishes Fresnel diffraction from Fraunhofer diffraction? A) Frequency of light used. B) Shape of aperture. C) Angle of incidence. D) Type of wavefronts involved. Show Answer Correct Answer: D) Type of wavefronts involved. 47. In Young's double slit experiment, a thin uniform sheet of glass is kept in front of the two slits, parallel to the screen having the slits. The resulting interference pattern will satisfy: A) The fringe width will decrease. B) The fringe width will increase. C) The interference pattern will remain unchanged. D) The fringes will shift. Show Answer Correct Answer: D) The fringes will shift. 48. In interference pattern A) We get the fringes of same intensity and same width. B) We get the fringes of same intensity but different width. C) We get the fringes of different intensity but same width. D) We get the fringes of different intensities and different widths. Show Answer Correct Answer: A) We get the fringes of same intensity and same width. 49. What is meant by monochromatic light? A) A light source with one speed only. B) A light source with only white light. C) A light source that is coherent. D) A light source with one wavelength only. Show Answer Correct Answer: D) A light source with one wavelength only. 50. In the phenomena of Diffraction of light when the violet light is used in the experiment is used instead of red light then, A) Fringe width increases. B) Fringe width decreases. C) No change in fridge width. D) Colour pattern is formed. Show Answer Correct Answer: B) Fringe width decreases. 51. By a monochromatic wave, we mean A) A single ray of a single colour. B) Many rays of a single colour. C) A single ray. D) Wave having a single wavelength. Show Answer Correct Answer: D) Wave having a single wavelength. ← PreviousRelated 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 4Class 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