Definitions

Question 1

Photoelectric effect

Answer 1

It is the release of electrons from the surface of a metal when electromagnetic radiation is incident on it’s surface

Question 2

Threshold frequency

Answer 2

It is the minimum frequency of an e.m radiation required for a photon to eject an electron from the surface

Question 3

1- When does photoemission takes place ?

2- What can you say about threshold frequency of metals

Answer 3

1-It takes place instantaneously , there is no decay between illumination and emission
2-Different metals have different threshold frequency

Question 4

-What about emission? Talk about frequency and intensity

Answer 4

• Emission or not it only depends on the frequency of radiation.
• It does not depend not then intensity of radiation

Question 5

For a given frequency…

Answer 5

The rate of emission of photoelectrons is proportional to the intensity of radiation

Question 6

Stopping voltage

Answer 6

It is the minimum value of the potential difference necessary to stop the electron flow