Testing and maintenance of electrical machine MCQ-1

1. Wires carrying electric current are covered with good insulator for safety purpose. It is called _

(A) Fuse
(B) Circuit breaker
(C) Rope
(D) Cable

2. A safety device which connected in series with live wire in circuit to protect equipments is called

(A) Switch
(B) Indicator
(C) Fuse
(D) None of these

3. Electric shock by high voltage and high current stops breating ______

(A) For longer period
(B) Momentarily
(C) Both (a) and (b)
(D) None of these

4. Electric fire is extinguished by ______

(A) Liquid extinguisher
(B) Wet chemical extinguisher
(C) CO2 extinguisher
(D) None of these

5. Preventive maintenance is done due to the following :

(A) It increases the life of machine
(B) It reduces the breakdown to minimum
(C) It increases the efficiency of machine
(D) All of the above

6. Factors considered during preparing maintenance schedule is/are

(A) Checking of stationary parts
(B) Checking of movable parts
(C) Checking of surrounding in which the equipment has to work
(D) All of the above

7. Causes of breakdown of machines are

(A) Negligence
(B) Incorrect installation
(C) Both (a) and (b)
(D) None of these

8. Monthly maintenance of motor includes :

(A) Checking of winding for their proper insulation
(B) Checking of air gap between stator and rotor
(C) Both (a) and (b)
(D) None of these

9. The function of conservator in a transformer is :

(A) To prevent flow of air into the tank
(B) To prevent flow of moisture into the tank
(C) To take care of expansion and contraction of oil
(D) None of these

10. In power transformer, the breather is provided to

(A) Take fresh air for increasing cooling effect
(B) Arrest flow of moisture into the tank
(C) Control the level of oil in the tank
(D) Filter transformer oil

11. Buchholz relay is used in :

(A) Welding transformer
(B) Oil cooled transformer
(C) Air cooled transformer
(D) None of these

12. Oil in the transformer is used for providing

(A) Cooling to the winding
(B) Insulation to the winding
(C) Protection against atmospheric humidity
(D) All of the above

13. In order to determine suitability of the oil in transformer tests carried out are :

(A) Acidity test
(B) Breakdown test
(C) Crackle test
(D) All of the above

14. Isolators used in transmission line are capable of breaking ______

(A) Fault current
(B) Load current
(C) Charging current
(D) None of these

15. The basic function of a circuit breaker is ______

(A) To produce arc
(B) To ionise the surrounding arc
(C) To extinguish the arc
(D) None of these

16. Earth tester is used to measure :

(A) Insulation resistance
(B) Earth resistance
(C) Volatage
(D) None of these

17. The main objective of foundation for electrical machine is :

(A) To support the weight of machine
(B) To maintain the alignment of the machine
(C) To provide firm for the machine
(D) All of the above

18. Cause of vibration in electrical machine is :

(A) Electrical causes
(B) Mechanical causes
(C) Both (a) and (b)
(D) None of these

19. Magnetisation current in three phase induction motor depends on :

(A) Load
(B) Rating
(C) Type of motor
(D) Air gap

20. For proper parallel operation, alternators must have the same ______

(A) Speed
(B) Voltage rating
(C) KVA rating
(D) Excitation