Dual Nature of Radiation and Matter Mock Test – Class 12 Physics

1. Radiation of wavelength falls on a metal of threshold wavelength . The ratio of incident photon energy to work function is

2. A symbol-unit record contains one mismatched entry. Pick the mismatched entry.

3. The statement “any bright light gives current” is not a correct description of a photoelectric cell because

4. Use the comparison below.

The missing wavelengths for and are respectively

5. A comparison table for photons and ordinary massive particles is shown below.

The row that should be rejected is

6. The maximum speed of photoelectrons from a metal is . Taking and , the stopping potential is closest to

7. A radiation beam has wavelength , while another has wavelength . For individual photons, the energy of the radiation is

8. Consider the following statements about matter waves and uncertainty.
Statement I: Wave-particle duality suggests that microscopic particles cannot always be described by exact classical paths.
Statement II: Matter waves require a material medium like sound waves.
Statement III: A highly localized matter wave is associated with a spread in momentum values.

9. For a monochromatic beam falling normally on a fixed metal area, intensity is best connected with photon rate by the relation

10. Consider the following statements about types of electron emission.
Statement I: Photoelectric emission is caused by suitable radiation.
Statement II: Thermionic emission is caused by heating.
Statement III: Field emission is caused by energetic particle impact.

11. A clean metal surface shows no photoelectric emission for radiation of frequency , but emits electrons for radiation of frequency . Both beams are made very intense. The most suitable conclusion is

12. A radiation packet has energy . Express this energy in , using .

13. For light travelling in vacuum, increasing the frequency while keeping the speed fixed makes the wavelength

14. A unit check for gives

15. A particle of mass has kinetic energy and is moving non-relativistically. Its de Broglie wavelength may be written as

16. In a straight-line graph of versus for a metal, the slope is . Taking , the value of obtained from the graph is closest to

17. A stopping-potential graph has vertical intercept when is plotted against . The work function of the metal is

18. In a -versus-incident-frequency graph for a photoemissive metal, the slope of the straight line is

19. Assertion: External energy is needed for electron emission from a metal surface.
Reason: Electrons at the metal surface are bound and must overcome a minimum escape-energy requirement.

20. A monochromatic beam of power falls on a photoemissive surface. Each photon has energy , the work function is , and the quantum efficiency is . If all emitted electrons are collected, the saturation current and stopping potential are closest to

21. Study the two cases described below.

What happens to the measured current in the two cases?

22. The following graph description is given.

The correct comparison is

23. In an electron diffraction experiment, first-order constructive scattering occurs from planes separated by at Bragg angle . Using , the accelerating potential is closest to

24. The relation tells us that photon momentum is measured in the unit

25. A beam of suitable light falls on a clean metal surface and electrons are emitted from the surface. This phenomenon is called

26. For a surface whose threshold frequency is , with , the work function is closest to

27. A student says, “The photoelectric effect and Davisson-Germer experiment are both explained by the same formula .” The best correction is that

28. Match the observation or idea with the aspect it supports.

The proper matching is

29. Use the graph description below.

The slope of the graph is

30. In Hallwachs-type observation, ultraviolet light falling on a negatively charged zinc plate causes rapid discharge mainly because

31. A mixed data record is shown below.

The row that needs correction is

32. A particle of mass and charge is accelerated from rest through potential . Another particle has mass and charge , and is accelerated through the same . Their de Broglie wavelengths satisfy

33. With work function and incident photon energy , Einstein’s photoelectric equation gives as

34. A quantity has the unit . In dual-nature calculations, it is most naturally identified as

35. Read the situation below and answer the question.

The correct interpretation is

36. A table from a photoelectric current experiment is shown below.

Which assessment is appropriate?

37. For , radiation of photon energy is incident on a metal. The stopping potential corresponding to the fastest photoelectrons is

38. A monochromatic beam of intensity falls on an area . Each photon has energy . Using , the number of photons incident per second is

39. A qualitative uncertainty statement is being used with matter waves. Which statement is most suitable for a dual-nature discussion?

40. Given work function and stopping potential for the incident radiation, the photon energy is

41. At fixed above-threshold frequency, increasing the intensity of radiation on a metal surface mainly increases

42. The threshold frequency and threshold wavelength of the same metal are related in such a way that their product equals

43. Increasing the accelerating potential in a Davisson-Germer experiment mainly changes the diffraction condition because it changes the electrons'

44. Einstein’s photoelectric equation written in terms of stopping potential is

45. The strongest reason the photoelectric effect supports the particle nature of radiation is that

46. In the photoelectric effect, the symbol is used for

47. Under ideal threshold conditions, radiation of wavelength falls on a metal with . The fastest photoelectrons have

48. A photoelectric tube is operated with . At , the current just becomes zero. At large positive , the current becomes . The maximum kinetic energy and collected electron rate at saturation are respectively

49. A photoelectron has . Using , the maximum speed is found from

50. In electron emission from a metal, the term “surface phenomenon” is most appropriate because