Date | November 2019 | Marks available | 2 | Reference code | 19N.2.HL.TZ0.11 |
Level | Higher level | Paper | Paper 2 | Time zone | 0 - no time zone |
Command term | Draw | Question number | 11 | Adapted from | N/A |
Question
Monochromatic light of very low intensity is incident on a metal surface. The light causes the emission of electrons almost instantaneously. Explain how this observation
In an experiment to demonstrate the photoelectric effect, light of wavelength 480 nm is incident on a metal surface.
The graph shows the variation of the current in the ammeter with the potential of the cathode.
does not support the wave nature of light.
does support the photon nature of light.
Calculate, in eV, the work function of the metal surface.
The intensity of the light incident on the surface is reduced by half without changing the wavelength. Draw, on the graph, the variation of the current with potential after this change.
Markscheme
«low intensity light would» transfer energy to the electron at a low rate/slowly ✔
time would be required for the electron «to absorb the required energy» to escape/be emitted ✔
NOTE: OWTTE
«in the photon theory of light» the electron interacts with a single photon ✔
and absorbs all the energy OR and can leave the metal immediately ✔
NOTE: Reference to photon-electron collision scores MP1
✔
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NOTE: Allow reading from the graph of leading to an answer of 1.2 «eV».
similar curve lower than original ✔
with same horizontal intercept ✔