Name of the College : Valliammai Engineering College
Subject : Protection And Switchgear
Website : valliammai.co.in
Document Type : Question Bank
Download Model/Sample Question Paper :
QUESTION BANK : https://www.pdfquestion.in/uploads/valliammai.co.in/372-Protection%20And%20Switchgear.pdf
Valliammai Protection & Switchgear Question Paper
Question bank
UNIT I
INTRODUCTION :
PART A :
1. What is surge absorber? How do they differ from surge diverter?
2. What is meant by insulation co-ordination?
3. Define the terms a) pick up value b) Reset value
Related : Valliammai Engineering College EE2403 Special Electrical Machines Question Bank : www.pdfquestion.in/381.html
3. What is time setting and plug setting multiplier ?
4. What are the causes of over voltages?
5. Define the term arcing ground
6. How the transmission lines are protected against direct lightning strokes?
7. What is a Peterson Coil?
8. List the merits and demerits of solid grounding
9. Defined the term switch gear
10. What type relay is best suited for long distance very high voltage transmission lines?
11. Define selectivity of protective relaying
12. Mention the different sources of over voltages in power system
13. List the basic requirements of lightning arrester
14. What are the demerits of a resistance grounded system?
15. Defined Breaker time
16. What are the causes over voltages on power system?
17. What is meant by voltage surge?
18. What is ground wire?
19. What is a protector tube?
20. Define basic impulse level.
21. A relay is connected to 400/5 ratio current transformer with current setting of 150%.Calculate the Plug Setting Multiplier when circuit carries a fault current of 4000 A
21. List the common protective scheme which are used for modern power system protection
22. What is the need for calculation short circuit current
23. What is the need for power system earthing
24. What is the need for protection
25. What are the protective zone of the power system
26. List at least two merits of resistance grounded system
27. How is arcing around avoided
PART B :
1. Describe the essential qualities of a protective relaying
2. Briefly explain the various methods of overvoltage protection of Overhead transmission line
3. With a neat block diagram, explain the operating principle of Peterson coil
4. Discuss the symmetrical components methods to analyze an unbalanced system
5. Write short note on surge absorber
6. Discuss the basic ideas of insulation coordination in the practical power System
7. Discuss and compare the various methods of neutral earthing
8. What do you understand by a zone of protection? Discuss various types of Zones of protection.
9. Describe types of lightning arrester
10. What are the requirements of a ground wire for protecting power conductors against direct lightning stroke? Explain how they are achieved in practice .
UNIT II
OPERATING PRINCIPLES AND RELAY CHARACTERISTICS
PART A
1. List the basic requirements of protective relay
2. What are the merits of mho relay?
3. Write the applications of attracted armature type electromagnetic relay
4. What are the different types of electromagnetic relays?
5. What is an under frequency relay?
6. What are the uses of Buchholz’s relay?
7. What is meant by drop off / pick up ratio?
8. What is the need of relay coordination?
9. What are the different inverse time characteristics of over current relays? Mention how characteristics can be achieved in practice for an electromagnetic relay.
10. What are the advantages of static relays?
11. Write the applications of distance relay.
12. What type relay is best suited for long distance very high voltage transmission lines?
13. What is meant by relay operating time?
14. Write the function of earth fault relay
15. List out the applications of static relays
16. Compare Static and Electromagnetic relay
17. What are the advantages of over current relays over electromagnetic types?
18. Define the term pilot with reference to power line protection.
19. What are the features of directional relay?