Question 1: What are the various dielectric materials according to their physical nature?
Question 2: Describe about surge voltages their distribution and control?
Question 3: Describe in brief the different numerical methods available for estimation of electrical field distribution in dielectric media?
Question 4: Discuss in brief about charge simulation method for solving field problems and estimation potential distribution.
Question 5: Describe the relative benefits and drawbacks of different numerical methods for solution of field problems?
Question 6:
a) Obtain the number of collision/second and the average time between two collisions, if the average velocity of the gas in the gap is 500m/s and mean free path is 107 m.
b) Derive the expression for collision cross-section in terms of mean free path.
Question 7: Describe in detail about thermal breakdown method in commercial liquids.
Question 8:
a) Describe short term and long term breakdown mechanisms which occur in a composite solid dielectrics.
b) Describe in brief about various solid dielectrics used in practice.
Question 9: Write brief notes on:
a) Photo-ionization.
b) Secondary ionization.
Question 10: Define Townsend's first and second ionization coefficients. Describe the Townsend's criterion for a spark breakdown.
Question 11: Describe about Paschan’s Law of break down in gases?