11 November 2011

Electrical Lab Viva Questions DC Machines

Viva Questions-DC machines

1.Why Series motors cannot be started without load?
3. What are the applications of DC series motors?
4. What is back emf and its significance in DC motor?
5. How speed is controlled in DC shunt motor?
6. Why starter is required in DC motor for starting?
7. What is critical resistance in DC motor?
8. What are the different losses in DC motor?
9. What is Armature Reaction in DC motor and its impact?
10. What is Commutation failure?
11. Advantages of Dummy windings in DC motors?
12. On what principle does DC motor operates?
13. What are the applications of DC Shunt motors?
14. What is the typical brush drop in DC motors?
15. Draw different characteristic curves of DC motors?
16. By carrying out brake test on DC motors what we can understand?
17. Explain Fleming's Left hand and Right hand rule and which rule applies to motor and Generator



No comments: