Electrical Machines Which of the following transformer insulating oil generally used in India? Olefin based insulating oil. Naphtha based insulating oil. Aromatics based insulating oil. Paraffin based insulating oil. Olefin based insulating oil. Naphtha based insulating oil. Aromatics based insulating oil. Paraffin based insulating oil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The synchronous motor can be started by providing damper winding in its rotor circuit. any of the above methods. coupling it with a small AC induction motor called the pony motor. coupling it with a DC compound motor. providing damper winding in its rotor circuit. any of the above methods. coupling it with a small AC induction motor called the pony motor. coupling it with a DC compound motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 4575.4 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 963.8 r.p.m. 4575.4 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 963.8 r.p.m. 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 varying the speed. changing the field excitation. varying the applied voltage. changing the load. varying the speed. changing the field excitation. varying the applied voltage. changing the load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A small air gap in poly phase induction motor helps to reduce chance of crawling. increase starting torque. reduce chance of cogging. reduce magnetizing current. reduce chance of crawling. increase starting torque. reduce chance of cogging. reduce magnetizing current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a 3-phase, 4 pole, 50 Hz synchronous motor the frequency, pole number and the frequency are halved. The motor speed will be 375 rpm 75 rpm 3000 rpm 1500 rpm 375 rpm 75 rpm 3000 rpm 1500 rpm ANSWER DOWNLOAD EXAMIANS APP
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