What is dielectric breakdown, Physics

Assignment Help:

What is dielectric breakdown? Explain briefly the various factors contributing to breakdowns in dielectrics.

Ans.: Electric Breakdown: When the electric field applied across any substance exceeds threshold breakdown field for that substance, the insulator suddenly turns into a resistor, Here a large usually abrupt rise in electric current is produced small increase in electric voltage. Breakdown can be intentional and controlled of accidental. Lightning is the most familiar example of breakdown.   

Electrical breakdown in Gas: In a gas, the potential gradient may become high enough to accelerate the naturally present may become high enough to accelerate the naturally present ions to such velocities that cause further ionization upon collision with other atoms. The process is corona discharge. If the region of ionization does not extend between oppositely charged electrodes, if the ionization region the gap between electrodes breaking down the insulation provided by the gas the process is ionization discharge. When controlled by the ballast of a fluorescent lamp the process converts electric power to light.  

Electrical Breakdown in Solid: In a solid, when the electric field gradient exceeds valence bonds between atoms are broken and current flows. Such a disruptive current heats the solid abruptly. During electrical breakdown, any free charge carrier being accelerated by the strong electric field will have enough velocity to knock electrons from any atom it strikes. Rapidly the insulator becomes filled with mobile carriers due to creation of more and more charge carriers and its resistance drops. In are the outbreak of conductivity is called corona discharge or a spark. 

Application: Electrical breakdown can be useful in every day applications such as spark plugs for gasoline engines, electrical welding of metals of for metal melting in an electric arc fumace.     

 

 


Related Discussions:- What is dielectric breakdown

Define dipole movement and write its applications, Dipole moment = product ...

Dipole moment = product of magnitude of charge on any ONE OF THE ATOM and the distance between them.(e.d) Large Application in electrostats.To differentiate among Polar and non pol

Explain history of nuclear reaction, Explain history of nuclear reaction? ...

Explain history of nuclear reaction? Bigger nucleus bust to from two lighter nucleus and two or three neutrons is known as nuclear fission used for making atom bomb two lighter

Calculate time of immersion of body into the liquid, A streamlined body giv...

A streamlined body given relative density ρ1 falls into air from a height h1 on surface of a liquid of relative density ρ2 where ρ2 > ρ1. find out the time of immersion of body int

Setellite, Discusse about motion of satellite

Discusse about motion of satellite

Explain vector addition, Vector Addition While we become students of ph...

Vector Addition While we become students of physics and approach the job of adding vector quantities, we soon become aware of the fact in which the addition of two vector quant

State gauss law, State Gauss's law. The total flux of the electric fie...

State Gauss's law. The total flux of the electric field E over whichever closed surface is equal to 1/ε o times the net charge enclosed by the surface. That is φ = q / ε

Write the symbol sad truth table of an and gate, Write the symbol sad truth...

Write the symbol sad truth table of an AND gate define how this gate is realised in practice by using two diodes.

Explain inertia and mass, Inertia and Mass: Newton's 1st law of motion ...

Inertia and Mass: Newton's 1st law of motion describes that "an object at rest stays at rest and an object in motion stays in motion with the similar speed in the similar direc

Heat, 2 liters of water at 80 celsius is found into a plastic bucket contai...

2 liters of water at 80 celsius is found into a plastic bucket containing 10 liters of water at 20 celsius what is the final temp of the mixture. specific capacity of water is 1 c

Determine the bending moment, Determine the Shear Force in kN rounded to 1 ...

Determine the Shear Force in kN rounded to 1 DP and Bending Moment in kN.m rounded to 1 DP at point C in the beam when the UDL on the beam is P52 kN/m (as for the previous question

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