If the source voltage of a DC motor is increased, which of the following will decrease? Starting torque, operating speed, full load current. Starting torque. Operating speed. Full load current. TRUE ANSWER : ? YOUR ANSWER : ?
A motor operates in stable region at which of the following slip? high slip region low slip region unity slip both 1 and 2 TRUE ANSWER : ? YOUR ANSWER : ?
Which motor used in Lathe machine? D.C. cumulative compound motor. D.C . series motor. None of these D.C. shunt motor. TRUE ANSWER : ? YOUR ANSWER : ?
In an auto-transformer, power is transferred through conduction process only. None of these induction process only. both A and B. TRUE ANSWER : ? YOUR ANSWER : ?
1 KVA, 230 V, 50 Hz, single phase transformer has an eddy current loss of 30 watts. The eddy current loss when the transformer is excited by a dc source of same voltage will be zero watt 30 W more than 30 W less than 30 W TRUE ANSWER : ? YOUR ANSWER : ?
The direction of rotation of a DC compound motor can be reversed by interchanging armature connections. armature or field connections. shunt field connections. series field connections. TRUE ANSWER : ? YOUR ANSWER : ?
An IM cannot run at synchronous speed because induction motor will become synchronous motor. air friction will prevent it. rotor torque will not be produced. none of above. TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following rotor requires damper winding? Salient pole rotor. None of these Both type rotor. Cylindrical rotor. TRUE ANSWER : ? YOUR ANSWER : ?
Compensating windings are used in DC generators None of these to provide path for the circulation of cooling air. to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. TRUE ANSWER : ? YOUR ANSWER : ?
In induction motor especially the cage rotors slots are nearly parallel to shaft axis. This is called slip. skewing. cogging. crawling. TRUE ANSWER : ? YOUR ANSWER : ?