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

A simple wheel and axle, A simple wheel and axle Remove the cover from ...

A simple wheel and axle Remove the cover from a pencil sharpener and bind a string tightly around the end of the shaft. Bind a weight of various kilograms to the end of the str

What is the significance of poynting vector, Write down the differential fo...

Write down the differential form of Poynting theorem. What is the significance of Poynting vector?

Special Relativity, What would happen if the principle of relativity is pro...

What would happen if the principle of relativity is proved wrong?

Adiabatic reversible expansion of an ideal gas, Derive the mathematical exp...

Derive the mathematical expression PV r = constant for an ideal gas undergoing adiabatic reversible expansion.

How many pounds does one gallon of water weigh, How many pounds does one ga...

How many pounds does one gallon of water weigh One wine calculates or US gallon of water weighs 8.34 pounds. An Imperial Gallon is ten pounds of water at 62F and 30 inches of

Classical electrodynamics jackson, Hi Do you have expert can help me to sol...

Hi Do you have expert can help me to solve coupl problems from classical electrodynamics Jackson ch11 and ch12

Define the working of the television, Define the Working of The Television ...

Define the Working of The Television This leads to a technology that works to create the picture every time you turn on your television or your computer monitor. This same techno

What are plastics, Plastics are (A) Good conductors of heat. (B) ...

Plastics are (A) Good conductors of heat. (B) Good conductors of electricity. (C) Bad conductors of electricity. (D) High density. Ans: Plastics are Bad

What are major fiber sensors, What are major fiber sensors? Major Fiber...

What are major fiber sensors? Major Fiber Sensors: a. Point sensors: Bragg gratings extended period gratings, Fabry-Perot interferometers. Maximum temperature can be as high

Determine free electrons per ge atom, At 400.0 K, germanium has 1.13 x 10 1...

At 400.0 K, germanium has 1.13 x 10 15 free electrons/cm 3 . How many free electrons per Ge atom are there at this temperature? At 400.0 K, silicon has 4.54 x 10 12 free

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