4. Question: In the photon picture of light, the light intensity I is related to the A.magnitude of electric field E. B.frequency of light f. C.de Broglie wavelength. D.number of photons per second E.number of photons per second per area.

5. Question: When the intensity I of monochromatic light shining on a metal surface in vacuum is increased, the maximum kinetic energy of emitted electrons A.increases. B.stays the same. C.decreases.

6. Question: When the frequency f of light shining on a metal surface in vacuum is increased, the maximum kinetic energy of emitted electrons A.increases. B.stays the same. C.decreases.

7. Question: When the area of the metal surface is increased for light of fixed light intensity I and frequency f, the maximum kinetic energy of emitted electrons A.increases. B.stays the same. C.decreases.

8. Question: Monochromatic red light with intensity I illuminates a metal surface and produces a certain stopping voltage V red. If now monochromatic blue light with intensity I also illuminates the metal, the new stopping voltage V will A.increase B.stay the same C.decrease

10. Question: True or false: the randomness of the appearance of monoenergetic electrons on a screen that have passed through a 2- slit experiment one-by-one disappears if one of the slits is closed.

11. Question: True or false: the collision of a photon with an electron in the Compton effect is an elastic collision (energy of the photon is unchanged).