Einstein''s photoelectric equation, Physics

Q. What is Einstein's photoelectric equation? Explain the laws of photoelectric effect with the help of this equation.

Photoelectric Effect : The emission of electron from a metal plate when illuminated by light of any other radiation of suitable wavelength or frequency is called photoelectric effect.

This is one of the experimental evidences of quantum particle nature of light or radiation. This effect was discovered by Hertz when ultraviolet light was allowed to fall on a zinc plate. He observed that electrons are emitted when light of certain frequency is incident on plate as shown in Fig. the electrons so emitted are known as photoelectrons and the current, so produced due to flow of photoelectrons is termed as photoelectric current.

Experimental Set up to Study Photoelectric Effect : Fig. Shows a typical setup used to study photoelectric effect. In an evacuated tube, two electrodes P1 and P2 are connected to an external electric circuit to provide desired potential difference. Electrode P1 behaves as anode and P2 behaves as cathode.

These two electrodes are connected to a microammeter, commutator, voltmeter and a battery as shown in Fig. Microammeter is used to measure current produced due to the flow of photoelectrons, thus current is not very big quantity so we use a very sensitive microammeter to measure it.

Commutator is used to change the polarity of potential on the plates i.e. P1 and P2 can be made positive or negative with respect to each other with the help of commutator. Potential difference between these two metal plates can be measured with the help of commutator. Potential difference between two metal plates can be measured with the help of voltmeter and the potential difference can be changed with the help of potential divider. Light of different intensities and different frequencies could be made to fall on the plate P1.

Einstein's Photoelectric Equation : According to this theory, light travels in the form of energy packages called photons. The velocity of these photons is equal to that of light and their energy is Hv, where 'h' is Planck's constant and v is the frequency f light. When light falls on a metal surface, a photon is completely absorbed by a single electron is the surface. A part of this energy is used in ejecting the electrons against the attraction of the rest part of energy is given to the electron as their kinetic energy so therefore according to energy conservation law.

Posted Date: 7/11/2012 3:10:57 AM | Location : United States







Related Discussions:- Einstein''s photoelectric equation, Assignment Help, Ask Question on Einstein''s photoelectric equation, Get Answer, Expert's Help, Einstein''s photoelectric equation Discussions

Write discussion on Einstein''s photoelectric equation
Your posts are moderated
Related Questions
candela; cd The basic SI unit of luminous intensity described as the luminous intensity in a given direction of a source which emits monochromatic photons of frequency 540 x 1

A Plane polarized light is incident on a piece of quartz cut parallel to its axis. Evaluate the least thickness for which ordinary ray and extraordinary ray combine

Q. If a single force acts on an object, the object accelerates. yse it is definately true. Newton's second law.

explain and illustrate how pure spectrum is formed

A bar has a 20N weight at one end. You have a weight of 15N to hang somewhere on the bar so that the bar is in equilibrium. Where would you hang the 15 N weight on each of these ba

Explain moment of inertia Moment of inertia is the term used to calculate or quantify the amount of mass located at an object's extremities. For instance if all the mass of an

On the planet Newtonia, a simple pendulum having a bob with mass 1.25 kg and a length of 185.0 cm takes 1.42 seconds, when released from rest, to swing through an angle of 12.5 deg

The matter consists of one or more basic substances called elements. An element is a substance whose all atoms are alike. Cohesion between atoms arises atoms because of interaction

Given the following thermodynamic information, develop the Ag-CN-H 2 O Eh-pH diagram for a solution containing 1 × 10 -3 M [Ag] and 5 × 10 -3 M [CN] at 25 o C. Please show all wo