Question

What is Photo electric effect?​

Answer 1

➝ Photo electric effect :-

$\Large \star$The phenomenon of ejection of electrons from the surface of metals when light of suitable frequency strikes is called as photo electric effect.

The electrons ejected are called photo electrons.

The minimum frequency required to eject electrons is called threshold frequency.

The photoelectric effect is readily exhibited by alkali metals like k, Rb and Cs.

A part of the energy of photon is used to escape the electron from the attractive forces and the remaining energy is used in increasing the kinetic energy of electron.

• E = W + K.E

where W = work function or Threshold energy.

W = hv$_0$ ⠀⠀⠀⠀⠀hv = hv$_0$+KE

K.E = hv - hv$_0$ = $\sf\dfrac{hc}{\lambda}$ - $\sf \dfrac{hc}{\lambda _0}$

where, v$_0$ = Threshold frequency.

In photo electric effect the number of photo electrons emitted is proportional to intensity of incident light.

Answer 2

Answer:

Photo Electric Effect

The phenomenon of emission of electron from the metal surface when radiation of suitable frequency are incident on them.

Hope this helps u