Electrical Machines What is the necessity of copper brushes in a dc motors? To increase the flux cutting by the rotor. None of these. To convert alternating supply current to direct current. To absorb the mechanical shocks produced during running condition. To increase the flux cutting by the rotor. None of these. To convert alternating supply current to direct current. To absorb the mechanical shocks produced during running condition. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Select the motor that should not be started on no load? Shunt motor. Compound motor. Series motor. Brushless DC motor. Shunt motor. Compound motor. Series motor. Brushless DC motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to any of the above. under commutation. too rapid reversal of current. over commutation. any of the above. under commutation. too rapid reversal of current. over commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Dissolve gas analysis of transformer oil is carried out to determine condition of transformer oil. condition of bushing stud. condition of bushings. condition of transformer. condition of transformer oil. condition of bushing stud. condition of bushings. condition of transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In travelling cranes for swing action which motor is preferred? DC series motor. AC slip ring IM. Reluctance motor. Capacitor type induction motors. DC series motor. AC slip ring IM. Reluctance motor. Capacitor type induction motors. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will increase to a value greater than 1.25 times 220 V not change and remain at 220 V increase to 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V increase to a value greater than 1.25 times 220 V not change and remain at 220 V increase to 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V ANSWER DOWNLOAD EXAMIANS APP
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