Unit IV
Dielectric materials
1. Define dielectric constant.
2. Define polarisation of a dielectric material.
3. Name the four polarisation mechanisms.
4. What is electronic polarisation?
5. What is ionic polarisation?
6. What is orientational polarisation?
7. What is space-charge polarisation?
8. What is meant by local field in a dielectric?
9. Define dielectric loss and loss tangent.
10. Define dielectric breakdown and dielectric strength.
11. Mention the various breakdown mechanisms.
12. What is intrinsic breakdown?
13. What is thermal breakdown?
14. What is chemical and electrochemical breakdown?
15. What is discharge breakdown?
16. What is defect breakdown?
17. Compare active and passive dielectrics.
18. What are the requirements of good insulating materials?
19. What are the differences between polar and non-polar molecules?
20. What are the dielectrics?
21. What are ferroelectric materials? Give example.