Energy Meter Theory - MCQs with answers
Q1. The instrument which works only with dc isA. Electrolytic motor
B. Mercury motor
C. Induction motor
D. Both (a) and (b)
View Answer / Hide AnswerANSWER: D. Both (a) and (b)
Q2. The electrolytic energy meters are essentiallyA. A true watt-hour meter
B. An ampere hour meter
C. Either watt-hour or ampere hour meter
D. Neither watt-hour nor ampere hour meter
View Answer / Hide AnswerANSWER: B. An ampere hour meter
Q3. An electrolytic ampere hour meter can be converted into watt-hour meter byA. Multiplying them by the voltage of the circuits in which it is used
B. Multiplying them by the current of the circuits in which it is used
C. Multiplying them by the power of the circuits in which it is used
D. Cannot be converted
View Answer / Hide AnswerANSWER: A. Multiplying them by the voltage of the circuits in which it is used
Q4. Commutator type meters can be used forA. Ac supply
B. Dc supply
C. Both ac and dc supply
D. None of these
View Answer / Hide AnswerANSWER: C. Both ac and dc supply
Q5. In case of motor meters, the speed of rotation isA. Directly proportional to the current in case of ampere hour meter and to power in case of watt-hour meter
B. Directly proportional to the current in case of ampere hour meter and inversely proportional to the power in case of watt-hour meter
C. Inversely proportional to the current in case of ampere hour meter and directly proportional to the power in case of watt-hour meter
D. Inversely proportional to the current in case of ampere hour meter and to power in case of watt-hour meter
View Answer / Hide AnswerANSWER: A. Directly proportional to the current in case of ampere hour meter and to power in case of watt-hour meter
Q6. In motor meters, the speed control of the rotating system is done by usingA. Permanent magnet
B. Train of gear wheels and dials
C. Pinion
D. All of these
View Answer / Hide AnswerANSWER: A. Permanent magnet
Q7. Commutator motor meters are A. Ampere hour meter
B. True watt-hour meter
C. Either ampere hour meter or true watt-hour meter
D. None of these
View Answer / Hide AnswerANSWER: C. Either ampere hour meter or true watt-hour meter
Q8. The induction type single-phase watt-hour meters usesA. Control spring
B. Pointer
C. Brake magnet and spindle
D. All of these
View Answer / Hide AnswerANSWER: C. Brake magnet and spindle
Q9. In induction watt-hour meter, due to shunt magnet the torque is not zero power factor. It can be compensated by usingA. Shading ring
B. Power factor compensator
C. Drilling holes in the disc on a diameter
D. Both (a) and (b)
View Answer / Hide AnswerANSWER: D. Both (a) and (b)
Q10. For friction compensation in an induction watt-hour meter is done by makingA. The ratio of the shunt magnet flux and series magnet flux large with the help of two shading bands
B. The ratio of the series magnet flux and shunt magnet flux large with the help of two shading bands
C. The ratio of the shunt magnet flux and series magnet flux large with the help of three shading bands
D. The ratio of the series magnet flux and shunt magnet flux large with the help of three shading bands
View Answer / Hide AnswerANSWER: A. The ratio of the shunt magnet flux and series magnet flux large with the help of two shading bands