Question

It is the phenomenon of the emission of electrons from a metallic surface when light of a suitable frequency is incident on it. The emitted electrons are called photoelectrons. Nearly all metals exhibit this effect with ultraviolet light but alkali metals like lithium, sodium, potassium, cesium, etc. show this effect even with visible light. It is an instantaneous process, i.e., photoelectrons are emitted as soon as the light is incident on the metal surface. The number of photoelectrons emitted per second is directly proportional to the intensity of the incident radiation. The maximum kinetic energy of the photoelectrons emitted from a given metal surface is independent of the intensity of the incident light and depends only on the frequency of the incident light. For a given metal surface, there is a certain minimum value of the frequency of the incident light below which emission of photoelectrons does not occur.

Photoelectrons are emitted when a zinc plate is ______.

पर्याय

• Heated

• hammered

• Irradiated by ultraviolet light

• subjected to a high pressure

Answer 1

Photoelectrons are emitted when a zinc plate is irradiated by ultraviolet light.