The threshold wavelength of a metal is λ0. Light of wavelength slightly less than λ0 is incident on an insulated plate made of this metal. It is found that photoelectrons are emitted for some time and after that the emission stops. Explain.
Answers
when a light of suitable frequency is incident on a metal insulated plate,the electron emit out of the metal surface.the following electron are photoelectron which generally get charged once the light falls on it.the paticular phenomenon is called as photoelectric effect.
e=h/k,where e stands for energy of the electron emitted out,h is plack constant which is equal to 6.626*10 to power minus 34 and k denote for the wavelength.
this is the formula for the above mentioned phenomenon when no other light is present.when we provide a light of suitable wavelength then the energy level decreses and it reaches to it's saturation level.after saturation there is no more emission of electron.
e=h*(1/k-1/k0)where k0 is the threshold wavelength.
Explanation:
- When there is an incidence of the wavelength’s light less than λ0 on the metal surface, the metal’s free electrons will receive more energy and gets released from the metal surface.
- The metal plate will then be insulated and there will be no connectivity with the battery.
- There will not be the replacement of the metal’s free electrons by the other electrons. So, after some time, the emission of photoelectron will stop.