Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two dc machines A and B, using the same conductor material, have armature circuit resistances of 0.4 Ω and 1.2 Ω respectively. Of the two machines, B is bigger than A for the same current rating A is bigger than B for the same current rating both are of the same size for the same current rating A is bigger than B for the same voltage rating B is bigger than A for the same current rating A is bigger than B for the same current rating both are of the same size for the same current rating A is bigger than B for the same voltage rating ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 0 Volt. 1500 Volt. 2000 Volt. 1600 Volt. 0 Volt. 1500 Volt. 2000 Volt. 1600 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods of speed control is not affected through stator side? Change of supply frequency. Change of supply voltage. Change of rotor resistance. Change of number of pole. Change of supply frequency. Change of supply voltage. Change of rotor resistance. Change of number of pole. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC series generator, the terminal voltage with increase in load will increase gradually and then stay at rated voltage remain nearly constant decrease increase to rated voltage and then may decrease increase gradually and then stay at rated voltage remain nearly constant decrease increase to rated voltage and then may decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The total core loss of a 400 V, 50 Hz transformer is 2400W, when it is supplied by 200 V, 25 Hz loss is 800W. Calculate eddy current loss and hysteresis loss? 1400W, 1000W 800W, 1600W 1000W , 1400W 1600W, 800W 1400W, 1000W 800W, 1600W 1000W , 1400W 1600W, 800W ANSWER DOWNLOAD EXAMIANS APP