Electrical Machines In a 3 - Φ IM with line frequency f1 and winding factor kw1 and kw2 for stator and rotor respectively the ratio of per phase stator winding emf E1 to per phase rotor winding emf E2 at standstill is given by E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50Hz, the emf in the rotor will have a frequency of 1.5Hz 51.5Hz 2.5Hz 48.5Hz 1.5Hz 51.5Hz 2.5Hz 48.5Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying number of poles. Both (A) and (B). By varying supply voltage. By varying the supply frequency. By varying number of poles. Both (A) and (B). By varying supply voltage. By varying the supply frequency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Wave winding is prefered for which of the following rating? low current and low voltage low current and high voltage high current and low voltage high current and high voltage low current and low voltage low current and high voltage high current and low voltage high current and high voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The full load copper loss and iron loss of transformer are 6400W and 5000W respectively. The copper loss and iron loss at half load will be respectively? 3200 W and 2500 W 1600 W and 1250 W 1600 W and 5000 W 3200 W and 5200 W 3200 W and 2500 W 1600 W and 1250 W 1600 W and 5000 W 3200 W and 5200 W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines With the increase in speed of DC motor Both back emf as well as line current fall. Back emf increase but line current falls. Back emf falls and line current increase. Both back emf as well as line current increase. Both back emf as well as line current fall. Back emf increase but line current falls. Back emf falls and line current increase. Both back emf as well as line current increase. ANSWER DOWNLOAD EXAMIANS APP
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