This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Physics Part Ii > Class 12 Physics (Part Ii) Chapter 11 Dual Nature Of Radiation And Matter – Quiz 1 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part Ii) Chapter 11 Dual Nature Of Radiation And Matter Quiz 1 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The momentum of photon of energy 1 MeV in kgms$^{-1}$ will be A) 10$^{-22}$. B) 5 x 10$^{-22}$. C) 0.33 x 10$^{6}$. D) 7 x 10$^{-24}$. Show Answer Correct Answer: B) 5 x 10$^{-22}$. 2. The slope of the stopping potential vs frequency graph: A) Changes with time. B) Changes with intensity of light. C) Changes with frequency. D) Constant for any material or any situation. Show Answer Correct Answer: D) Constant for any material or any situation. 3. WHICH of the following has minimum stopping potential/ A) YELLOW. B) VIOLET. C) RED. D) BLUE. Show Answer Correct Answer: C) RED. 4. According to the de Broglie hypothesis, which of the following statements is applicable to thewavelength of a moving particle? A) Inversely proportional to its momentum. B) Directly proportional to its momentum. C) Directly proportional to its energy. D) Inversely proportional to its energy. Show Answer Correct Answer: A) Inversely proportional to its momentum. 5. A light of wavelength 5000 A$^{0}$ falls on a photosensitive plate with photoelectric work function 1.90 eV. Kinetic energy of the emitted photo-electrons will be (h=6.62 x 10$^{-34}$ Js) A) 0.58 eV. B) 0.1 eV. C) 2 eV. D) 1.581 eV. Show Answer Correct Answer: A) 0.58 eV. 6. Observation:Bright blue light liberates photoelectrons fromthe surface of lithium but red light from thesame intensity does not give off any electronsat all.Explanation:Photons of blue light carry more energy thanphotons of red light because the frequency ofblue light is higher than the frequency of redlightDOES THE EXPLANATION EXPLAIN THE OBSERVATION? A) YES. B) NO. C) All the above. D) None of the above. Show Answer Correct Answer: A) YES. 7. Two photons, each of energy 2.5 eV are simultaneously incident on sodium metal surface the work function of sodium is 2.75 eV, then from its surface ..... will be emitted. A) More than two electrons. B) Not a single electron. C) Two electrons. D) One electron. Show Answer Correct Answer: B) Not a single electron. 8. In discharge tube, ionization of enclosed gas is produced due to collision between A) Negative electrons & neutral atoms/molecules. B) Positive ions & neutral atoms/molecules. C) Photons & neutral atoms/molecules. D) Neutral gas atoms/molecules. Show Answer Correct Answer: A) Negative electrons & neutral atoms/molecules. 9. TWO particles have equal momentum. what is the ratio of their de Broglie wavelength? A) 3. B) 2. C) 0.5. D) 1. Show Answer Correct Answer: D) 1. 10. The saturation current is proportional to the ..... of radiation A) Intensity. B) Time of travel. C) Frequency. D) Target material. Show Answer Correct Answer: A) Intensity. 11. Photoelectric emission is a/an ..... process. A) Instantaneous. B) Slow. C) Very slow. D) Fast. Show Answer Correct Answer: A) Instantaneous. 12. What is the significance of the Davisson-Germer experiment in understanding the nature of matter? A) It demonstrated the process of nuclear fission. B) It proved the existence of parallel universes. C) It established the speed of light as the ultimate speed limit. D) It confirmed the wave-particle duality of matter. Show Answer Correct Answer: D) It confirmed the wave-particle duality of matter. 13. What is the phenomenon where electrons are emitted from a material when it is exposed to light? A) Piezoelectric effect. B) Electromagnetic effect. C) Thermoelectric effect. D) Photoelectric effect. Show Answer Correct Answer: D) Photoelectric effect. 14. Light of frequency 1.9 times the threshold frequency is incident on photo-sensitive material. If the frequency ishalved, and intensity is doubled, the photoelectric current becomes A) Double. B) Quadrupled. C) Half. D) 0. Show Answer Correct Answer: C) Half. 15. A photocell employs photoelectric effect to convert A) Change in the frequency of light into a change in the electric voltage. B) Change in the intensity of illumination into a change in photo electric current. C) Change in the frequency of light into a change in the electric current. D) Change in the intensity of illumination into a change in the work function of the photo cathode. Show Answer Correct Answer: B) Change in the intensity of illumination into a change in photo electric current. 16. The photo current in an experiment on photoelectric effect increases if A) The intensity of the source is increased. B) The exposure time is decreased. C) The intensity of the source is decreased. D) The exposure time is increased. Show Answer Correct Answer: A) The intensity of the source is increased. 17. An electron is moving with an initial velocity v=v$_{0}$ i and is in a magnetic field B=B$_{0}$j. Then its de Broglie wavelength A) Remains constant. B) Increases with time. C) Decreases with time. D) Increases and decreases periodically. Show Answer Correct Answer: A) Remains constant. 18. The stopping potential depends upon the ..... of the fastest electron. A) Velocity. B) Mass. C) Charge. D) Density. Show Answer Correct Answer: A) Velocity. 19. The minimum required frequency required to remove an electron from an atom is called: A) Thershold frequency. B) Critical frequency. C) Infliction frequency. D) None of the above. Show Answer Correct Answer: A) Thershold frequency. 20. The energy spent in releasing a photoelectron is called photoelectric ..... of the metal A) Absorption energy. B) Work function. C) Ionization potential. D) Energy. Show Answer Correct Answer: B) Work function. 21. Threshold frequency of potassium is 3 x 10$^{14}$ Hz. The work function is A) 1.0 x 10$^{-19}$ J. B) 2 x 10$^{-19}$ J. C) 4 x 10$^{-19}$ J. D) 0.5 x 10$^{-19}$ J. Show Answer Correct Answer: B) 2 x 10$^{-19}$ J. 22. According to the quantum theory, light is emitted in the form discrete bundles of energy called ..... A) Waves. B) Mesons. C) Corpuscles. D) Photons. Show Answer Correct Answer: D) Photons. 23. If in a photoelectric experiment the wavelength of incident radiation is reduced from 6000 A$^{0}$ to 4000 A$^{0}$ then A) Stopping potential will decrease. B) The value of work function will decrease. C) Kinetic energy of emitted electron will decrease. D) Stopping potential will increase. Show Answer Correct Answer: D) Stopping potential will increase. 24. The value of stopping potential when the frequency of light is equal to the threshold frequency is A) Minimum. B) Infinity. C) Maximum. D) Zero. Show Answer Correct Answer: D) Zero. 25. The work function value of molybdenum is A) 4.28. B) 2.14. C) 5.65. D) 4.17. Show Answer Correct Answer: D) 4.17. 26. Hallwachs experiment set-up is used to study: A) Photo electric effect. B) Diffraction of light. C) Tyndal effect. D) Raman effect. Show Answer Correct Answer: A) Photo electric effect. 27. A photosensitive surface emits photoelectrons when red light falls on it. Will the surface emit photoelectrons when blue light is incident on it? A) Yes. B) No. C) All the above. D) None of the above. Show Answer Correct Answer: A) Yes. 28. The emission of electron is possible by A) Photoelectric effect. B) Thermionic effect. C) Both photoelectric effect & thermionic effect. D) None of these. Show Answer Correct Answer: C) Both photoelectric effect & thermionic effect. 29. Light exhibits ..... duality A) Gas-plasma. B) Solid-liquid. C) Particle-wave. D) Liquid-gas. Show Answer Correct Answer: C) Particle-wave. 30. Photoelectric current is ..... proportional to the number of photoelectrons emitted per second. A) Inversely. B) Directly. C) First directly and then inversely. D) None of these. Show Answer Correct Answer: B) Directly. 31. Which of the following has highest specific charge? A) Positron. B) Proton. C) Helium. D) None of these. Show Answer Correct Answer: A) Positron. 32. A beam of cathode rays is subjected to crossed electric and magnetic fields. The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by A) . B) . C) . D) . Show Answer Correct Answer: A) . 33. The cathode is coated with a material of low work function because A) High work function should be achieved later. B) It is transparent. C) It is low in cost. D) A large number of photo electron can be got. Show Answer Correct Answer: D) A large number of photo electron can be got. 34. The photon behaves as a particle in ..... phenomenon A) Diffraction. B) Interference. C) Polarization. D) Emission. Show Answer Correct Answer: D) Emission. 35. The magnitude of saturation photoelectric current depends upon A) Frequency. B) Intensity. C) Work function. D) Stopping potential. Show Answer Correct Answer: B) Intensity. 36. The speed of the fastest photoelectron emitted from a surface of threshold wavelength 600 nm, when the surface isirradiated by light of wavelength 400 nm is A) 2 x 10$^{7}$ m s$^{-1}$. B) 2 x 10$^{6}$ m s$^{-1}$. C) 9.3 x 10$^{5}$ m s$^{-1}$. D) 6 x 10$^{5}$ m s$^{-1}$. Show Answer Correct Answer: D) 6 x 10$^{5}$ m s$^{-1}$. 37. The photoelectric threshold frequency of a metal is 'v'. When light of frequency '4v' is incident on the metal, the maximum kinetic energy of the emitted photo electrons is A) 3hv. B) 5hv. C) 5/2(hv). D) 4hv. Show Answer Correct Answer: A) 3hv. 38. When the intensity of a light source is increased A) The number of photons emitted by the source in unit time increases. B) Total energy of the photons emitted per unit time decreases. C) More energetic photons are emitted. D) Faster photons are emitted. Show Answer Correct Answer: A) The number of photons emitted by the source in unit time increases. 39. Two metals A and B have work functions of 2 eV and 5 V respectively. When light of wavelength 400 nm is incident, electrons are emitted from A) A. B) B. C) Both A and B. D) Neither A nor B. Show Answer Correct Answer: A) A. 40. In the photoelectric effect, if the intensity of incident light increases, the A) Photo electric current increases. B) K.E. of emitted electrons increases. C) K.E. of emitted electrons decreases. D) Photo electric current decreases. Show Answer Correct Answer: A) Photo electric current increases. 41. If the kinetic energy of photo electron is found to be 16 J, whose mass is $m_e$ A) $\sqrt[]{4m_e}$. B) $\sqrt[2]{\frac{1}{m_e}}$. C) $\sqrt[4]{\frac{2}{m_e}}$. D) $\sqrt[]{\frac{4}{2m_e}}$. Show Answer Correct Answer: C) $\sqrt[4]{\frac{2}{m_e}}$. 42. Velocity of photo is proportional to in terms of frequency 'v' will be A) V. B) $\frac{1}{\sqrt{v}}$. C) $\sqrt{v}$. D) $v^2$. Show Answer Correct Answer: C) $\sqrt{v}$. 43. Heisenberg's Uncertainty Formula is ..... A) $\Delta x\cdot\Delta v\approx\frac{h}{2\pi}$. B) $\Delta x\cdot\Delta p=h$. C) $\Delta x\cdot\Delta v\ge\frac{h}{2\pi}$. D) $\Delta x\cdot\Delta p\approx\frac{h}{2\pi}$. Show Answer Correct Answer: D) $\Delta x\cdot\Delta p\approx\frac{h}{2\pi}$. 44. Two light rays having photon of energy 1.8 eV are falling on metal surface having work function 1.2 eV . The stopping potential applied to stop emitting photo electrons will be A) 0.6 eV. B) 3 eV. C) 1.2 eV. D) 1.4 eV. Show Answer Correct Answer: A) 0.6 eV. 45. For a given frequency of the incident radiation, the stopping potential ..... of its intensity. A) Is directly proportional. B) Is inversely proportional. C) Is independent. D) None of these. Show Answer Correct Answer: C) Is independent. 46. A particle is dropped from a height H. The de Broglie wavelength of the particle as a function of height is proportional to A) H0. B) H $^{-1/2}$. C) H $^{1/2}$. D) H. Show Answer Correct Answer: B) H $^{-1/2}$. 47. Which is the correct form of Einstein's photoelectric equation? A) $K_{\max}=h\left(\nu_o-\nu\right)$. B) $\phi_o=K_{\max}+h\nu$. C) $K_{\max}=h\nu+\phi_o$. D) $E=K_{\max}+\phi_o$. Show Answer Correct Answer: D) $E=K_{\max}+\phi_o$. 48. In various experiments on photo electricity dealing with the stopping potential dependence on frequency of incident radiation the conclusion was that stopping potential A) Depends on the light intensity. B) Depends on the frequency. C) Depends on the initial current. D) Is independent of frequency. Show Answer Correct Answer: B) Depends on the frequency. 49. What is the threshold frequency in the context of the photoelectric effect? A) The frequency at which light changes from a wave to a particle. B) Maximum frequency of light required to eject electrons from a metal surface. C) Minimum frequency of light required to eject electrons from a metal surface. D) The frequency at which light becomes invisible to the human eye. Show Answer Correct Answer: C) Minimum frequency of light required to eject electrons from a metal surface. 50. If 'h' is plank's constant, the momentum of a photon of wavelength 0.01 A$^{0}$ A) 10$^{2}$ h. B) 10$^{12}$ h. C) H. D) 10$^{-2}$ h. Show Answer Correct Answer: B) 10$^{12}$ h. 51. A monochromatic source of light is placed at a distance d from a metal surface. Photoelectrons are ejected at a raten and with maximum KE = E. If the source is brought to a distance d/2, the rate and maximum KE of photoelectronsbecome, respectively, A) 2n and E. B) 2n and 2E. C) 4n and E. D) N and 4E. Show Answer Correct Answer: C) 4n and E. 52. Wave theory of light predicted that ..... which is false A) "No. of photoelectrons increases, as intensity increases ". B) "Kinetic energy of the electron increases, as frequency increases ''. C) "As in intensity increases, kinetic energy of the electron increase s". D) "As intensity increases, Photocurrent also increases". Show Answer Correct Answer: C) "As in intensity increases, kinetic energy of the electron increase s". 53. Explain the concept of wave-particle duality. A) Wave-particle duality refers to the separation of particles and waves. B) Wave-particle duality is the concept of particles being only particle-like. C) Particles can exhibit both wave-like and particle-like properties. D) Particles can only exhibit wave-like properties. Show Answer Correct Answer: C) Particles can exhibit both wave-like and particle-like properties. 54. In various experiments on photo electricity the stopping potential for a given frequency of the incident light A) Is incident of the radiation intensity. B) Is inversely proportional to the radiation intensity. C) Is independent of radiation intensity. D) Is proportional to radiation intensity. Show Answer Correct Answer: A) Is incident of the radiation intensity. 55. Who Proved that electron was wave? A) Lenard and Hallwach. B) Davisson and Germer. C) Michelson and Morley. D) Cavendish. Show Answer Correct Answer: B) Davisson and Germer. 56. Photoelectric effect was first discovered by A) Hertz. B) Einstein. C) Germer. D) Newton. Show Answer Correct Answer: A) Hertz. 57. A material particle with a rest mass mo is moving with speed of light c. The de-Broglie wavelength associated is given by: A) Mac. B) Zero. C) None of these. D) All of these. Show Answer Correct Answer: A) Mac. 58. An electron is accelerated through a potential difference of 1000 V. The velocity acquired by the electron is A) 1.5 x 10 $^{8}$ m s$^{-1}$. B) 1.5 x 10 $^{7}$ m s$^{-1}$. C) 2.0 x 10 $^{8}$ m s$^{-1}$. D) 1.88 x 10 $^{7}$ m s$^{-1}$. Show Answer Correct Answer: D) 1.88 x 10 $^{7}$ m s$^{-1}$. 59. Which is De-Broglie Wavelength Formula for Elementary particles? A) $\lambda=\frac{hc}{p}$. B) $\lambda=\frac{h}{p}$. C) $p=\frac{h\lambda}{c}$. D) $p=\frac{h\nu}{\lambda}$. Show Answer Correct Answer: B) $\lambda=\frac{h}{p}$. 60. Work function of a metal is the A) Minimum energy required by an electron to escape from the metal surface. B) Energy required by an electron to get absorbed in the metal surface. C) Maximum energy required by an electron to escape from the metal surface. D) Energy required by an electron to escape from the metal surface. Show Answer Correct Answer: A) Minimum energy required by an electron to escape from the metal surface. Next →Related QuizzesScience QuizzesClass 12 QuizzesClass 12 Physics (Part Ii) Chapter 11 Dual Nature Of Radiation And Matter Quiz 2Class 12 Physics (Part Ii) Chapter 10 Wave Optics 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 QuizClass 12 Physics (Part Ii) Chapter 9 Ray Optics And Optical Instruments Quiz 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books