Question

What did the results of photoelectric-effect experiments establish?

A) Electrons are emitted as soon as low-intensity, high-frequency light hits a metal surface.

B) Electrons are never emitted if low-intensity light waves strike a metal surface.

C) Electrons are emitted if low-intensity light has been incident on metal for a long time.

D) Electrons are emitted if high-intensity light has been incident on metal for a long time.

Answer 1

Electrons are emitted as soon as low-intensity, high-frequency light hits a metal surface.

Answer 2

If light of sufficient frequency falls on the metal surface then due to this energy of light electrons will move out of the metal surface

this phenomenon is known as photoelectric effect

As per Einstein's equation we know that

`h\\u = \phi + KE`

here we know that

`\phi` = work function

so if light have sufficient frequency so that the work function of metal is less than the energy of photon then it will surely eject the electrons and photo electric effect will occur

So here correct answer will be

A) Electrons are emitted as soon as low-intensity, high-frequency light hits a metal surface.