If the peak of a sine wave is 13 V, the peak-to-peak value is
A). 6.5 V
B). 13 V
C). 26 V
D). None of the above
A sinusoidal current has an rms value of 14 mA. The peak-to-peak value is
A). 45.12 mA
B). 16 mA
C). 39.6 mA
D). 22.6 mA
Change of D.C. excitation of a synchronous motor changes
A). Applied voltage of the motor
B). Motor speed
C). Power factor of power drawn by the motor
D). Any of the above
The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as
A). pull-up torque
B). pull-in torque
C). pull-out torque
D). none of the above
A synchronous motor connected to infinite bus-bars has at constant full load, 100% excitation and unity power factor. On changing the excitation only, the armature current will have
A). no change of power factor
B). lagging power factor with over-excitation
C). leading power factor with under-excitation
D). leading power factor with over-excitation