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

Alternate representation for complex poles, Alternate Representation for Co...

Alternate Representation for Complex Poles Complex poles can be combined to yield a quadratic term in the partial fraction expansion. The representation may best be illustrated

Explain the signals hold and sid, Explain the signals HOLD, READY and SID ...

Explain the signals HOLD, READY and SID HOLD indicates that a peripheral such as DMA controller is requesting the use of address bus, data bus and control bus. READY is used to

Determine rc and resistance, Q. A silicon npn BJT is biased by the method s...

Q. A silicon npn BJT is biased by the method shown in Figure, with R E = 240 , R 2 = 3000 , and V CC = 24 V. The operating point corresponds to V BEQ = 0.8V, I BQ = 110 µA,

Electromechanical and electronic switching system, Q. Compare electromechan...

Q. Compare electromechanical switching system with electronic switching system. Sr. No Electromechanical switching System Electroni

Develop and execute a pspice program, Develop and execute a PSpice program ...

Develop and execute a PSpice program to solve for the current I 2 in Figure.

Assignment question , An audio amplifier with feedback needs gain of approx...

An audio amplifier with feedback needs gain of approximately 500 in a 3-dB bandwidth extending from 60 Hz to 25 kHz. Assume this is accomplished using a feedback network with ß=0.0

Draw an electrical relay diagram, Draw an electrical relay diagram rung sho...

Draw an electrical relay diagram rung showing a N/O contact of CR1(coil) in series witha N/C contact of CR2(Coil), operating a lamp L1. A delay-on (TON) relay has a preset of 5.

Construction and working of analog type storage oscilloscope, Q.   Describe...

Q.   Describe in detail the construction and working of analog type storage oscilloscope. Explain the principle of secondary emission. Analog Storage Oscilloscopes: Storage o

Sampling of digital communication systems, Q. Sampling of digital communica...

Q. Sampling of digital communication systems? Sampling of an analog signal makes it discrete in time. A bandlimited signal can be recovered exactly from its samples, taken peri

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