In 1905, Albert Einstein explained the various laws of photoelectric emission on the basis of Planck.s quantum theory. According to Planck.s quantum theory, light radiations consists of tiny packets of energy called quanta. One quantum of light radiation is called a photon which travels with the speed of light. The energy of a photon is given by E= hv where, h is Planck.s constant and v is the frequency of light radiation. When a photon of energy hv falls on a metal surface, then the energy of the photon is absorbed by the electron and is used in following two ways:
(a) A part of energy is used to overcome the surface barrier and come out of the metal surface. This part of energy is called work function. It is expressed as ϕ0=hv0" role="presentation" style="display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 13px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: 0px; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(0, 0, 0); font-family: Lato, sans-serif; font-variant-ligatures: normal; font-variant-caps: normal; orphans: 2; widows: 2; -webkit-text-stroke-width: 0px; background-color: rgb(224, 234, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; position: relative;">ϕ0=hv0ϕ0=hv0.
(b) The remaining part of the energy is converted to the maximum kinetic energy of the emitted photoelectrons (12mvmax2)" relative;">∴Kmax=hv−ϕ0∴Kmax=hv-ϕ0
This equation is called Einstein.s photoelectric equation.
The uses of photoelectric cells are as follows:
(a) Used in burglar alarm and fire alarm and also used as photoelectric sensors, automatic switches in street lights.
(b) Used for reproduction of sound in cinema film, in television camera for telecasting seens and in phototelegraphy to control the temperature of furnace.
It consists of an evacuated glass tube with a photosensitive material as the cathode(C) and a collector plate acting as the anode(A). The incident light shines through a quartz window. A battery is connected to the cathode to facilitate evacuation of photoelectrons
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Answer:
In 1905, Albert Einstein explained the various laws of photoelectric emission on the basis of Planck.s quantum theory. According to Planck.s quantum theory, light radiations consists of tiny packets of energy called quanta. One quantum of light radiation is called a photon which travels with the speed of light. The energy of a photon is given by E= hv where, h is Planck.s constant and v is the frequency of light radiation. When a photon of energy hv falls on a metal surface, then the energy of the photon is absorbed by the electron and is used in following two ways:
(a) A part of energy is used to overcome the surface barrier and come out of the metal surface. This part of energy is called work function. It is expressed as ϕ0=hv0" role="presentation" style="display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 13px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: 0px; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(0, 0, 0); font-family: Lato, sans-serif; font-variant-ligatures: normal; font-variant-caps: normal; orphans: 2; widows: 2; -webkit-text-stroke-width: 0px; background-color: rgb(224, 234, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; position: relative;">ϕ0=hv0ϕ0=hv0.
(b) The remaining part of the energy is converted to the maximum kinetic energy of the emitted photoelectrons (12mvmax2)" relative;">∴Kmax=hv−ϕ0∴Kmax=hv-ϕ0
This equation is called Einstein.s photoelectric equation.
The uses of photoelectric cells are as follows:
(a) Used in burglar alarm and fire alarm and also used as photoelectric sensors, automatic switches in street lights.
(b) Used for reproduction of sound in cinema film, in television camera for telecasting seens and in phototelegraphy to control the temperature of furnace.
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Photoelectric effect experimental setup
It consists of an evacuated glass tube with a photosensitive material as the cathode(C) and a collector plate acting as the anode(A). The incident light shines through a quartz window. A battery is connected to the cathode to facilitate evacuation of photoelectrons