Question

The electrons are emitted in the photoelectric effect from a metal surface ___________.

• A. only if the temperature of the surface is high
• B. only if the frequency of the incident radiation is above certain threshold value
• C. at a rate independent of the nature of the metal
• D. none of the above

Answer 1

Answer: (B)

only if the frequency of the incident radiation is above certain threshold value

A metal exhibits photoelectric effect that when a light of certain frequency, greater than the threshold frequency of metal surface, falls on the metal then the surface starts to emit electrons from its surface known as photo-electrons.
If frequency of light is less than the threshold frequency, no emission of photo electrons takes place.