Important Questions of Overvoltage Protection:

1. What is a voltage surge ? Draw a typical lightning voltage surge.

2. Discuss the causes of overvoltages.

3. What is lightning ? Describe the mechanism of lightning discharge.

4. Describe the various types of lightning stroke.

5. What are the harmful effects of lightning ?

6. How do earthing screen and ground wires provide protection against direct lightning strokes ?

7. What is a surge diverter ? What is the basic principle of operation of a surge diverter ?

8. Write short notes on the following surge diverters:

(i) Rod gap diverter

(ii) Horn gap diverter

(iii) Expulsion type (livelier

(iv) Multigap diverter

9. Discuss the construction, principle and working of a valve type arrester.

10. What is a surge absorber ? Write a short note on Ferranti surge absorber.

11. Why are steep fronted surges more dangerous to power system equipment ?

12. Why is lightning accompanied by a thunder ?

13. Is the name lightning arrester appropriate ?

14. Why are surge diverters located very close to the equipment to be protected ?

15. Where will you use a surge absorber ?