If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then_____________?
(A) the stator current will be zero
(B) the stator current will be very small
(C) the stator current will be very high
(D) the back e.m.f. will be more than the supply voltage
(D) none of the above
The coupling angle or load angle of synchronous motor is defined as the angle between the__________?
(A) rotor and stator teeth
(B) rotor and the stator poles of opposite polarity
(C) rotor and the stator poles of the same polarity
(D) none of the above
The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as__________?
(A) locked-rotor torque
(B) synchronous torque
(C) pull up torque
(D) reluctance torque
If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will__________?
(A) stop
(B) run as induction motor
(C) function as static condenser
(D) burn with dense smoke
A synchronous machine with low value of short-circuit ratio has___________?
(A) lower stability limit
(B) high stability limit
(C) good speed regulation
(D) good voltage regulation
(D) none 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
For similar carrier and modulating signals, the line current used in CSI is_____________?
(A) Identical to line voltage in a VSI
(B) Identical to line current in VSI
(C) Identical to phase voltage in VSI
(D) Identical to phase voltage in CSI
During the commutation period in 3 phase converter, overlap time is____________?
(A) Dependent on the load current
(B) Dependent on the voltage
(C) Dependent on both the load current and load voltage behind the short circuit current
(D) Independent on both the load current and load voltage
The effects of EMI can be reduced by_____________?
(A) Suppressing emissions
(B) Reducing the efficiency of the coupling path
(C) Reducing the susceptibility of the receptor
(D) All of these
An SCR is made up of silicon because_____________?
(A) silicon has large leakage current than germanium
(B) silicon has small leakage current than germanium
(C) silicon has small leakage voltage than germanium
(D) silicon has large leakage voltage than germanium