NTPC Question-Paper

                                       NTPC Electrical Engineering Sample Paper

1. What is causal system? 

2. Shunt reactor is used in EHV transmission line for ?

3. 20w, 40W, & 200w lamps are connected to three phases if neutral wire breaks then which lamp will fuse first? 
1) 20 
2)40 
3)200 
4)three lamps will fuse together. 

4. Synchronous machine can be operated at both lagging and leading power factor ?

5 What does synchronous speed mean? 

6. Frequency of emf generated per rotation of rotor is equal to. ?

7. DC machine having wave winding is wounded as lap winding what will be the effect on emf generated ?

8. Which is remain unchanged in transformer action? 

9. In transformer windings are connected.? 

10. In general how transformer is rated? 

11. What is given on the name plate of motor? 
1) KW 
2) KVA 
3) output shaft power 

12. Short circuit test of transformer gives what? 

13. Transformer core are laminated for what purpose? 

14. What is supply voltage for heavy industry ?
1) 33KV 
2) 11KV 
3) 132 KV 
4) 66KV 

15. Basic structure SCR as a two transistor i.e. how they are connected? 

16. What is Triac? 

17. System admittance is (G+jB) what is reactive power absorbed if the voltage is V KV? 
(1)V (square)*B 
(2) V (square)*g . 

18. In series R-L circuit what is phase difference between the voltage drop across R and L? 

19. Power factor is cosine (delta ) delta is the angle between 
1) phase voltage phase current 
2) Line voltage lone current 
3) phase voltage line current 
4) line voltage phase current.

20. Laplace of exp (-at)?

21. For series R-L-C circuit the load will be capacitive if the frequency is 
1) greater than the resonant frequency 
2) less than the resonant frequency 

22. In Wiens bridge which circuit elements determine the frequency range? 

23. What is the output if two booster having duty cycle K and (K-1) are connected in series? 

24. If a DC shunt motor is loaded from unloaded condition what will be effect of on terminal voltage? 

25. A second wire system having one pole one right half of the s-plane. When the system will be stable? 

26. A system having repetitive pole what will be effect on the gain at the cross over frequency? 

27. Hollow conductor is used to reduce corona loss how does it reduce the loss? 

28. In DC machine how voltage is related to flux? 

29. Nature of current and voltage in the armature and at the terminal in DC machine. 

30. Motor acts on the principle of ..rule 

31. Which instrument measure both ac and dc? 

32. How the rotation of induction motor is reversed? 

33. If 3-phaseof a 3- phase balance load are reversed what will be the effect on the line current? 

34. If the rating of VAR absorber is 50M VAR at 400KV. What will the VAR absorbed by the absorber at 300KV? 

35. In regenerative breaking of DC series motor what is done?