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

Explain force, FORCE: "Force is that agency which causes a body to alte...

FORCE: "Force is that agency which causes a body to alter its state of motion or rest". It is denoted by F ?

Determine law of conservation of electric charge, Determine Law of Conserva...

Determine Law of Conservation of Electric Charge Law of Conservation of Electric Charge:  In any method, the net amount of electric charge formed is zero Force between charg

Inductors, Inductors are the electronic components designed especially for ...

Inductors are the electronic components designed especially for introducing a required amount of inductance in the circuit. They are coils of wires, wound around some magnetic mate

Determine tension in pulley problems, Three equal weights A, B, C of mass 2...

Three equal weights A, B, C of mass 2 kg each are hanging on a string passing over a fixed frictionless pulley as shown. Tension in the string connecting weights B and C is approxi

Is light from object pass through the location of the image, In structuring...

In structuring the image does light from the object necessarily pass through the location of the image? Ans: No In reality in the case of a plane mirror (defining the obje

Radio communication , Production of sound messages by a microphone in a rad...

Production of sound messages by a microphone in a radio station (studio). 1) Audio frequency generation. 2) Generation of r.f. carrier wave. 3) Modulation in a transmitter, b) 4

Define transverse waves , Particles of the medium implement simple harmonic...

Particles of the medium implement simple harmonic motion about their mean position in a direction perpendicular to the direction of propagation of wave motion. (i) It goes in th

Discovery of neutron, Write down a short note on the discovery of neutron. ...

Write down a short note on the discovery of neutron. Show the uses of radioisotopes.

What is the principle of generating ultrasonic waves, What is the principle...

What is the principle of generating ultrasonic waves? The general principle comprised in generating ultrasonic waves is to reasons some dense material to vibrate very quickly.

Unit of charges, Unit of Charges: The S.I unit of charge is Coulumb rep...

Unit of Charges: The S.I unit of charge is Coulumb represented by "c".

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