Which of the following is NOT true with respect to photoelectric emission?
1
Photoelectrons are emitted as soon as light falls on the metal.
2
Kinetic energy of the photoelectrons depends on the frequency of light but is independent of its intensity.
3
Number of photoelectrons emitted depends on both the intensity and frequency of light.
4
For emission of photoelectrons to occur, frequency of the incident radiation should be above the critical value of that metal.