Quantum Physics Flashcards
(8 cards)
Explain what is a photon.
It is quantum of energy of electromagnetic radiation.
Define work function energy of a metal
Work function energy of a metal is the minimum amount of energy that will remove an electron from the metal surface.
What is the threshold frquency
It is the minimum frequency of an incident photon that will remove an electron from the metal surface.
State the equation of photoelectric effect
The energy of a photon is equals to the sum of the work function energy of the metal and the maximum kinetic energy of ejected photoelectron
Explain what is photoelectric effect.
It is the emission of photoelectrons from a metal surface when electromagnetic radiation of a sufficiently high frequency is incident on it.
Why must phototube be evacuated?
It is to ensure that the photoelectrons travelling from emitter to collector are not deflected from their original paths by air molecules.
What is the purpose of making potential of collector more positive/negative than emitter?
To accelerate or decelerate the photoelectrons (speed related)
Define stopping potential
It is the minimum potential differencr between the metal and the collector that will prevent the most energetic photoelectron from reaching the collector, resulting in zero photocurrent
