[PDF] Competitive Exam MCQ For Electrical Engineering

DC MACHINE AND ALTERNATOR OR SYNCHRONOUS GENERATOR

This Multiple Choice Question set for helping propose for which student are government job aspirants.This Multiple Choice Question Set mainly focused on DC MACHINE AND ALTERNATOR OR SYNCHRONOUS GENERATOR.

DC MACHINE

1. Which DC motor know as Constant speed motor
A) DC Series Motor
B) Induction Motor 
C) DC Shunt motor
D) DC Cumulative Compound Motor
2. Which Motor Run at Over speed when noload?
 A) DC Series Motor
 B) DC Shunt Motor
C) DC Cumulative Compound Motor
D) None of the above
3. Lighting and Battery charging purpose use DC Motor?
 A) DC Series Motor
 B) DC Shunt Motor
C) DC compound Motor
 D) None of the above

4. Which type Speed Control use in DC motor=

A) by flux and armature resistance

B) by flux and terminal voltage

C) by armature resistance and voltage

D) buy flux, armature resistance & terminal voltage

5. For the purpose of separate excitation which field is most preferred?

 A) shant field

 B) series field

 C) both a&b

 D) none of the above

6. Armature torque of DC series motor which proportion with armature current

 A) directly squire d

 B) inversely

 C) inverse square d

 D) directly

7. In DC motor torque increased 2 times with armature current increase

 A) 8 Times

 B) 4 Times

 C) 2 Times

 D) None of the above

8. What is the Disadvantage of high starting current DC Motor

 A) Burning the armature due to excessive Heating.

 B) damage the commutator and brush

 C) excessive voltage drop

 D) a,b &c

9. If Back Emf increase when Terminal voltage and armature resistance constant in dc motor the current Behaviour is-

 A) No change

 B) Increasing

 C) Decreasing

 D) none of the above

10. Mechanical Efficiency of DC motor Measured by

 A) output power /Mechanical power in armature(Eb Ia)

 B) Mechanical power in armature (Eb/Ia)/Input (V IL)

 C) Output/input

 D) None of the above

11. At Maximum developed mechanical power in DC motor Back Emf equal to

Of the Transformer-

 A) voltage

 B) voltage /2

 C) voltage/4

 D) None of the above

12. When Back Emf take Maximum value

 A) No - load

 B) Full load

 C) half load

 D) None of the above

13. Which loss change with speed in DC motor

 A) Copper loss

 B) Core loss

 C) friction loss

 D) None of the above

14. Constant Power Drive used speed control method is

 A) resistance control

 B) flux control

 C) voltage control

 D) None of the above

ALTERNATOR

15. For Rapidly change loads which Speed Control method use

 A) flux control

 B) Rheostatic speed control

 C) voltage control

 D) None of the above

16. In thermal power plant which Alternator use

 A) Low speed

 B) High speed

 C) AorB

 D) A & B both

17.A Salient-pole Rotor Alternator is-

 A) Large Diameter and short axial length

 B) Large diameter

 C) short axial length

 D) small diameter and very long axial

18. If 4 pole 50 hz 3 phase induction motor synchronous speed In thermal power plant Alternator Started by-

 A) Damper winding

 B) pony motor

 C) A or B

 D) None of the above

19. At the time of of parallel operation of an alternator power factor determine by

 A) load power factor

 B) prime movers speed

 C) field excitation

 D) none of the above

20. Over Excited Synchronous Motor behaves like a

 A) Capacitor Bank

 B) inductor

 C) reactor

 D) None of the above

21. Effect of cross magnetisation field on generated voltage is-

 A) sinusoidal

 B) sinusoidal with distortion

 C) non sinusoidal

 D) None of the above

22. A 2 pole 4 kv Alternator frequency 49.5 hz increase to 50 hz speed achieve with

 A) 2800-3000 RPM

 B) 2870-3000 RPM

 C) 2900-3000 RPM

 D) 2970-3000 Rpm

23. If need to increase the active power-

 A) by changing governor

 B) Increase excitation

 C) Increase the speed

 D) None of the above

24. If active power need to increasing -

 A) Excitation increase

 B) speed increase

 C) voltage increase

 D) None of the above

25. Salient pole Alternator speed is

 A) 100-300 RPM

 B) 1500-3000 RPM

 C) 400-500 RPM

 D) 120-400 RPM

26. Why cylindrical pole type Alternator small diameter and long axial length

 A) speed

 B) strong centrifugal force

 C) Torque

 D) None of the above

27. When Power factor is 1 the Alternator efficiency will be

 A)Half

 B) can not Determine

 C) LOW

 D) MAXIMUM

28. n Generators is connected parallel If frequency will try to increase which wiil increase 

 A) Excitation

 B) Input 

 C) Voltage

 D) None of the above

29. Where Mainly seen high speed turbine:

 A) Thermal power plant

 B) Hydroelectric power plant

 C) Gas power plant

 D) None of the above

30. If n Generators connected in busbar which parameter need to constant

 A) Voltage and frequency

 B) Voltage

 C) frequency

 D) None of the above

------------------------------------------------

Answer 

1. ... Answer is C)
2. ... Answer is B)
3. ... Answer is B)
4. ... Answer is A)
5. ...Answer is A)
6. ... Answer is A)
7. ... Answer is B)
8. ... Answer is D)
9. ... Answer is A)
10. ... Answer is B)
11. ... Answer is A)
12. ... Answer is B)
13. ... Answer is C)
14. ... Answer is B)
15. ... Answer is A)
16. ... Answer is B)
17. ... Answer is D)
18. ... Answer is A)
19. ... Answer is C)
20. ... Answer is D)
21. ... Answer is C)
22. ... Answer is A)
23. ... Answer is D)
24. ... Answer is B)
25. ... Answer is D)
26. ... Answer is B)
27. ... Answer is A)
28. ... Answer is A)
29. ... Answer is B)
30. ... Answer is A)

If you want to use this post as a question paper 

This is second part of  Multiple Choice Question set first part is

MCQ-1

------------------------------------------------

Others posts

ELECTRICAL ENGINEERING MCQ for Competitive Exam[PDF]

In Circuit Breaker Used Remote Operating Devices