This set of Electrical Measurements & Measuring Instruments Multiple Choice Questions & Answers (MCQs) focuses on “Errors in Dynamometer Wattmeter”.
1. Pressure coil of a wattmeter ________
a) has capacitance and inductance
b) has inductance and resistance
c) has resistance and capacitance
d) has only inductance
2. What is the effect of capacitance on wattmeter reading?
a) aiding the inductance
b) opposite to that of inductance
c) aiding the capacitance
d) opposite to that of resistance
3. Wattmeter reading is not affected by temperature.
4. Dynamometer type wattmeter has _________
a) strong magnetic field
b) intermediate magnetic field
c) weak magnetic field
d) no magnetic field
5. Wattmeter reading has errors induced by _________
d) mutual inductance
6. Current in a pressure coil of the Dynamometer type wattmeter ________
a) lags the applied voltage
b) leads the applied voltage
c) is in phase with the applied voltage
d) there is a phase difference of 90 degrees
7. Wattmeters are compensated for errors due to inductance by _________
a) using a series capacitor
b) using a parallel capacitor
c) using a series resistance
d) using a parallel resistance
8. Eddy currents are induced in solid metal parts within the thickness of the conductor.
9. What is the effect of frequency on the torque of a moving system?
a) torque is half of the frequency
b) torque is twice the frequency
c) torque is thrice the frequency
d) torque is four times the frequency