Explain polarization, Electrical Engineering

Assignment Help:

Explain Polarization.

Polarization: A dielectric has molecules the atomic nuclei of that are effectively fixed, related to each other. In absence of any external field all the electrons are distributed symmetrically round the nucleus at any time. While an electric field is applied the electrons of the atoms are acted on by that field. It causes a movement of the electrons that are displaced in a direction opposite to the electrons that are displaced in a direction opposite to the field. This movement is opposed through the attractive forces in between nuclei and electrons. And resultant effect is to separate the positive and negative charges in each molecule therefore they behave as electric dipoles. The strength of all dipole is specified by the dipole moment that in its simplest form, having two equal point charges of opposite sign ± Q separated, with a distance d.

As the dipoles are created the dielectric is said to be polarized or in a state of polarization seems the dielectric to be composed of many of elementary cylinders each of length l towards the applied field and of cross section δA. Assume that a uniform field of strength E is applied normal to the plates. It polarizes the dielectric inducing dipoles in all elementary cylinders, and charges δq appears on any end of the cylinder. The charge density, σ on the surface δA of the cylinder is specified by σ = (δq/ δA)(c/m2) = l (δq/ δA) = m/δV. Here m is the dipole moment and δV is the volume of the elementary cylinder. When the number of dipole per unit volume be N which is when N = 1/δV after that σ = Nm. The product Nm is termed as the polarization (P) of the dielectric and is the complete dipole moment established in unit volumes of the insulating medium. Therefore a dielectric subject to a homogeneous field carries a dipole moment P per unit volumes that may be written as P=Nm.


Related Discussions:- Explain polarization

Three-phase induction motor, Q. A 60-Hz, six-pole, wye-connected, three-pha...

Q. A 60-Hz, six-pole, wye-connected, three-phase induction motor, with the parameters R 1 = R 2 = 0.025  and Xl 1 = Xl 2 = 0.125 , is controlled by variable-frequency control

Determine the required value of the flux density, Q. A 100-turn coil in the...

Q. A 100-turn coil in the configuration of is rotated at a constant speed of 1200 r/min in a magnetic field. The rms induced voltage across the coil is 1 kV, and each turn has a le

Compute the speed of the rotor, A 3 phase 60 hertz induction motor has 8 po...

A 3 phase 60 hertz induction motor has 8 poles and operates with a slip of .05 for a certain load. Compute in r.p.m. the (a) Speed of the rotor with respect to the stator, (b

Circuit board packaging, Topics for the projects 1. Power supply design:...

Topics for the projects 1. Power supply design: One source, multiple source. Project process: 1.  Design(circuit analysis, diagram, list of components). 2.   Hardware e

Name the elements related to capacitance, Elements related to capacitance ...

Elements related to capacitance a.  Electric field: Area that surrounds the electric charge or charges system where the enhancing and reducing of electric force exists.

How to convert decimal to binary number, Q. How to convert Decimal to Binar...

Q. How to convert Decimal to Binary number? To convert the decimal to binary is slightly more difficult. There are two procedures (Methods) that may be used to convert from dec

Calculate the guage pressure, Questions: Part (a) A compressor inst...

Questions: Part (a) A compressor installed at a wharf (for loading container ships) is able to provide 6 bar.g pressure into the pressure receiver. The compressor is moved

Ramp type dvm, use of ranging and attenuator circuit

use of ranging and attenuator circuit

Find the power factor and current of the machine, Two identical three-phase...

Two identical three-phase, 33-kV, wye connected, synchronous generators operating in parallel share equally a total load of 12 MW at 0.8 lagging power factor. The synchronous react

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd