LEVEL 1

1. Explain why bus-coupler is used.
2. What is a ring-bus bar system? Explain in brief.
3. What is the difference between class 1 and class 2 power transformer?
4. Explain the working of buchholz relay?
5. What is a core type transformer?
6. What is a shell type transformer?
7. Explain the four oil preservation system designs?
8. Explain why instrument transformers are used ?
9. Go through the specification of any current transformer.
10. How are transmission lines classified as? Explain them in brief.
11. What are the advantages and limitations of high transmission lines voltage.
12. What is kelvin’s law and what are its limitations?
13. Distinguish between A.C and D.C resistance of a conductor. Why the two differ ?
14. What is a plain break oil circuit breaker and what is its major drawback?
15. Write a note on water type circuit breaker.
16. What are the different type of air blast circuit breaker and expalin them in brief.
17. What are the methods of arc extensions? Explain them in brief.
18. What is arc voltage?
19. What is restriking voltage?
20. What is recovery voltage?
21. What is current chopping?
22. What is resistance switching?
23. Explain the construction and working of SF6 Circuit breaker.
24. Types of SF6 Circuit breaker.
25. Explain the construction and working of Vacuum Circuit breaker.
26. What is the difference between isolator and circuit breaker?
27. Explain the importance of isolator in power system?

LEVEL 2

1. Write a short note on need for transformer maintenance and how often it is required.
2. Outline the procedure for maintenance of a transformer.
3. Explain the importance of variations in sound level in a transformer.
4. What are the different types of tests carried out on a transformer under maintenance?
5. Mention the precautions to be taken when a transformer has to be taken out for periodic maintenance.
6. Based on the lesser downtime available these days, how do you optimize the maintenance procedure?
7. What are the precautions to be taken during testing?