Electrical Machines A 4-pole dc generator runs at 1500 rpm. The frequencyof current in the armature winding is 50 Hz 25 Hz 100 Hz 0 Hz 50 Hz 25 Hz 100 Hz 0 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions is a dc motor provided with compensating winding used ? 1. Wide range of speed control above normal 2. Wide range of steady load variation with no speed control 3.Wide range of rapid variation in load Select the correct answer using the codes given below : Codes : 1 and 3 1 and 2 1, 2 and 3 2 and 3 1 and 3 1 and 2 1, 2 and 3 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronising power of a synchronous motor varies All of these directly as Xs2 directly as synchronous reactances Xs inversely as 1/Xs All of these directly as Xs2 directly as synchronous reactances Xs inversely as 1/Xs ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What will be the e.m.f. generated by a 4 pole lap connected DC Generator rotating at 1500 r.p.m.? Its flux per pole is 0.4 mWb and total no of armature conductors is 1000. 40 volts. 20 volts. 30 volts. 10 volts. 40 volts. 20 volts. 30 volts. 10 volts. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3- phase synchronous motor can operate over a wide range of power factors i.e. from lagging to leading power factor. This is achieved by changing the field excitation. changing the load. varying the applied voltage. varying the speed. changing the field excitation. changing the load. varying the applied voltage. varying the speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging in induction motor occurs when number of stator teeth - number of rotor teeth = even number. number of stator teeth - number of rotor teeth = 0. number of stator teeth - number of rotor teeth = negative number. number of stator teeth - number of rotor teeth = odd number. number of stator teeth - number of rotor teeth = even number. number of stator teeth - number of rotor teeth = 0. number of stator teeth - number of rotor teeth = negative number. number of stator teeth - number of rotor teeth = odd number. ANSWER DOWNLOAD EXAMIANS APP
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