Question 1:
What is meant by photoelectric effect?
Answer:
What is meant by photoelectric effect?
Answer:
Emission of electrons from a metal surface when shone on by light of a certain frequency.
Question 2:
Will a bright light emit more photoelectrons from a metal surface compared to a dim light of the same frequency?
Answer:
Will a bright light emit more photoelectrons from a metal surface compared to a dim light of the same frequency?
Answer:
Yes. The number of photoelectrons emitted depends on the number of photons that arrive on the metal surface.
Question 3:
State four characteristics of photoelectric effect that are obtained experimentally.
Answer:
– The higher the frequency of the light photons, the higher the kinetic energy of the photoelectrons emitted from the metal surface.
– The minimum frequency of light needed for a metal to emit electrons is the threshold frequency, f0 for the metal.
– The kinetic energy of photoelectrons does not depend on the intensity of light.
– Photoelectrons are emitted instantaneously when shone on by light.
State four characteristics of photoelectric effect that are obtained experimentally.
Answer:
– The higher the frequency of the light photons, the higher the kinetic energy of the photoelectrons emitted from the metal surface.
– The minimum frequency of light needed for a metal to emit electrons is the threshold frequency, f0 for the metal.
– The kinetic energy of photoelectrons does not depend on the intensity of light.
– Photoelectrons are emitted instantaneously when shone on by light.
Question 4:
Why are photoelectrons emitted instantaneously from a metal surface when it is illuminated by a light of certain frequency?
Answer:
Light consists of discrete energy packets, when a photon hits a metal surface, all its energy will be transferred to an electron in the metal.
With this, the photoelectron will be emitted instantanteously from the metal surface if the frequency of light is higher than the threshold frequency of the metal.
Why are photoelectrons emitted instantaneously from a metal surface when it is illuminated by a light of certain frequency?
Answer:
Light consists of discrete energy packets, when a photon hits a metal surface, all its energy will be transferred to an electron in the metal.
With this, the photoelectron will be emitted instantanteously from the metal surface if the frequency of light is higher than the threshold frequency of the metal.
Question 5:
Does an increase in the light intensity increase the kinetic energy of the photoelectrons? Why?
Answer:
No. The intensity of light only affects the number of photons arriving on the metal per second (photon rate).
The maximum kinetic energy of a photoelectron is influenced by the photon energy.
Increasing the light intensity will not increase the kinetic energy of the photoelectrons.
Does an increase in the light intensity increase the kinetic energy of the photoelectrons? Why?
Answer:
No. The intensity of light only affects the number of photons arriving on the metal per second (photon rate).
The maximum kinetic energy of a photoelectron is influenced by the photon energy.
Increasing the light intensity will not increase the kinetic energy of the photoelectrons.