Electrical Machines Transformer oil is used as both A and B. a coolant. an insulator. inert medium. both A and B. a coolant. an insulator. inert medium. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an induction machine is run at above the synchronous speed it acts as a synchronous motor an induction motor an induction generator None of these a synchronous motor an induction motor an induction generator None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The shaft of induction motor may be unbalanced due to poor lubrication. uneven air gap. overheating of winding. overload. poor lubrication. uneven air gap. overheating of winding. overload. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running with a divertor connected across its field winding. If the divertor resistance is reduced then the speed of the motor will increase. remain unaltered. become execessively high. decrease. increase. remain unaltered. become execessively high. decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a 3-phase induction motor operating in its stable region increases with increase in the load torque. decreases with decrease in the load torque. decreases with increase in the load torque. remains constant. increases with increase in the load torque. decreases with decrease in the load torque. decreases with increase in the load torque. remains constant. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 82.5% 78.5% 67.5% 72.5% 82.5% 78.5% 67.5% 72.5% ANSWER DOWNLOAD EXAMIANS APP
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