Ammeters And Voltmeters Theory - 3 - MCQs with answers
Q1. If the control spring of PMMC instrument is replaced by a another spring whose spring constant is higher than the previous one, then the damping ratio and natural frequencyA. Increases, decreases
B. Increases, increases
C. Decreases, decreases
D. Decreases, increases
View Answer / Hide AnswerANSWER: A. Increases, decreases
Q2. A PMMC instrument can be used as ammeter and as voltmeter with the help ofA. A low resistance shunt, a low series resistance
B. A low resistance shunt, a high series resistance
C. A high series resistance, a low resistance shunt
D. A low series resistance, a high shunt resistance
View Answer / Hide AnswerANSWER: B. A low resistance shunt, a high series resistance
Q3. In a PMMC instrument, if the control springs are eliminated the instrument can be used for measuring the quantity of electricity passed through the coil. This method is used forA. Ammeter
B. Voltmeter
C. Fluxmeter
D. Ballistic galvanometer
View Answer / Hide AnswerQ4. If the control springs of PMMC instrument is made up of large moment of inertia, then it can be used asA. Ammeter
B. Fluxmeter
C. Ballistic galvanometer
D. Wattmeter
View Answer / Hide AnswerANSWER: C. Ballistic galvanometer
Q5. The ratio of maximum current (with shunt) to the full scale deflection current (without current) in a permanent magnet moving coil instrument is known asA. Sensitivity
B. Multiplying factor
C. Multiplying power
D. Both (b) and (c)
View Answer / Hide AnswerANSWER: D. Both (b) and (c)
Q6. The multiplying factor of a PMMC used as ammeter isA. Directly proportional to the shunt resistance
B. Inversely proportional to the shunt resistance
C. Inversely proportional to the series resistance
D. Directly proportional to the series resistance
View Answer / Hide AnswerANSWER: B. Inversely proportional to the shunt resistance
Q7. The voltage multiplication factor of a PMMC instrument isA. Directly proportional to the required series resistance
B. Directly proportional to the shunt resistance
C. Inversely proportional to the shunt resistance
D. Directly proportional to the required series resistance
View Answer / Hide AnswerANSWER: A. Directly proportional to the required series resistance
Q8. A moving coil ammeter requires a potential difference of 0.4V across it for full scale deflection. It has fixed shunt resistance of 0.01 ohm with a coil circuit resistance of R = 1kohm. The value of shunt required to give full scale deflection when the total current is 10A is equal toA. 0.02 ohm
B. 0.04 ohm
C. 0.05 ohm
D. 0.06 ohm
View Answer / Hide AnswerQ9. A PMMC instrument gives full scale deflection at 40 mV potential difference and 8 mA current. What will be the required shunt resistance when it is used as ammeter of range 0 – 10 A?A. 0.002 ohm
B. 0.003 ohm
C. 0.004 ohm
D. 0.005 ohm
View Answer / Hide AnswerQ10. A permanent magnet moving coil gives full scale deflection at 40 mV potential difference and 8 mA current. What will be the required series resistance when it is used as voltmeter of range 0 – 200 V?A. 19556 ohm
B. 20163 ohm
C. 23884 ohm
D. 24995 ohm
View Answer / Hide Answer