Electrical Machines Hopkinss test in DC motor is conducted at ? No load. Low load. Full load. None of these. No load. Low load. Full load. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature MMF waveform of a DC machine is sinusoidal. rectangular. triangular. pulsating. sinusoidal. rectangular. triangular. pulsating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements: To control the speed of a dc shunt motor above the base speed over a reasonably wide range, the motor must 1. have compensating winding 2. have interpole winding 3. be started using a 3-point starter 4. be started using a 4-point starter Of these statements 1, 2 and 3 are correct 2 and 4 are correct 1, 2 and 4 are correct 1 and 3 are correct 1, 2 and 3 are correct 2 and 4 are correct 1, 2 and 4 are correct 1 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for voltage build up in self excited generator? All of these Field winding resistance should be less than critical resistance. Poles should contain residual flux. Field winding should be properly connected to armature winding. All of these Field winding resistance should be less than critical resistance. Poles should contain residual flux. Field winding should be properly connected to armature winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing the field of DC generator means increasing flux density by adding extra turns of winding. creating residual magnetism by a DC source. making the magnetic losses forces parallel. neutralising residual magnetism. increasing flux density by adding extra turns of winding. creating residual magnetism by a DC source. making the magnetic losses forces parallel. neutralising residual magnetism. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying the supply frequency. By varying supply voltage. Both (A) and (B). By varying number of poles. By varying the supply frequency. By varying supply voltage. Both (A) and (B). By varying number of poles. ANSWER DOWNLOAD EXAMIANS APP
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