Photo AI
A student uses a gold-leaf electroscope to investigate the photoelectric effect - Scottish Highers Physics - Question 7 - 2018
Question 7
A student uses a gold-leaf electroscope to investigate the photoelectric effect. A deflection of the gold leaf on the electroscope shows that the metal plate is char... show full transcript
Worked Solution & Example Answer:A student uses a gold-leaf electroscope to investigate the photoelectric effect - Scottish Highers Physics - Question 7 - 2018
Step 1
Step 2
Step 3
State what effect, if any, this has on the maximum kinetic energy of the photoelectrons ejected from the surface of the metal.
Answer
There is no change to the maximum kinetic energy of the photoelectrons. The irradiance does not affect the energy of the photons, so the maximum kinetic energy remains determined by the photon energy and work function.
Step 4
Add a line to the graph to show how the kinetic energy of the photoelectrons ejected from the aluminium plate varies as the frequency of the incident radiation increases.
Answer
Draw a line starting from the threshold frequency of 0.99 x 10^15 Hz, which intersects the kinetic energy axis at a point lower than that for the initial metal plate due to the lower threshold frequency.
Step 5
Explain why the photoelectric effect provides evidence for the particle nature of light.
Answer
The photoelectric effect shows that light consists of discrete packets of energy (photons) because individual photons can transfer enough energy to eject electrons from metal surfaces, rather than causing a continuous wave effect.