1.Autoreclosing feature in circuit breaker may help in maintaining system stability in most of the cases - explain.Autoreclosing feature in circuit breaker may help in maintaining system stability in most of the cases - explain.

2. Rate of rise of restriking voltage is considered to be an important parameter in respect of circuit breaking – explain.

3.Isolators do not have breaking capacity – explain

4. Breaking of capacitive current may result in severe voltage transients.

5.Discuss the role of main contact, arcing contact and blow out coil in air circuit breaker

6.Why alloys like Cu-Bi & Cu-Cr are considered to be suitable as the contact materials for vacuum circuit breaker?

7.How resistance switching is employed in air blast circuit breaker?

8.Which circuit breaker is free from current chopping problem? Why?

9.Explain the influence of power factor and neutral grounding on the recovery voltage transient.

10.Assume that a circuit breaker placed at the beginning of a long transmission line has to trip the line in the following cases: i) a close in fault ii) a fault far away from the circuit breaker location. What type of voltage transient are expected in the above mentioned cases? Explain your answer

11.Why symmetrical component analysis is used in fault analysis?

12.Why resistance and capacitance are generally ignored in fault analysis of high voltage systems?

13.What is meant by fault level of a system? Explain the implication of high and low fault level.

14. Why neutral grounding impedance appears in the zero sequence network only?