Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
Two 20-g ?atworms climb over a very thin wall, 10 cm high. One of the worms is 20 cm long, the other is wider and only 10 cm long. Which of them has done more work against grav
Will light go any length along the fiber? Each conductor has losses, and in the case of fiber optics, all these are sizeable. Light losses into the industry average 2 to 5 perc
Can illuminators be computer controlled? Practically all can be computer controlled as well as illuminators are not an exception. Color discs, mechanical shutters and lamp volt
what is clamper
The set of rectangular axes obeying the Newton's laws of motion and used to describe the position of a particle or an event are known as inertial frames of reference.
Regard as a pair of two identical capacitors. In which situation is the capacitance of the pair greater? Ans: The effective capacitance of a couple of capacitors in series
what is poission''s equation?Establish poisson''s equation for space distribution of charges.discuss its significance.
DRAW A GRAPH OF DISTANCE VERSUS TAN
Rule 1: In order to sum or subtract two physical quantities the quantities must have the similar dimension. The final physical quantity has the similar dimensions. Physical quantit
Give reason that ultrasonics not be produced by passing high frequency alternating current by a loud speaker At these high frequencies, inductive reactance is so high where is
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd