Electrical Machines What is the necessity of copper brushes in a dc motors? 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. To increase the flux cutting by the rotor. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following windings are necessary in case of all dc machines? lap winding wave winding open type winding closed winding lap winding wave winding open type winding closed winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately excited DC motor has an armature resistance of 0.5 Ohm. The supply voltage is 250V. Armature current is 20A and the speed of rotation is 1500 rpm. Find the torque developed? 15.6 Nm Zero 15.28 Nm 16.55 Nm 15.6 Nm Zero 15.28 Nm 16.55 Nm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC shunt generator working on load, the brushes are moved forward in the direction of rotation, as a result of this, commutation will improve and terminal voltage will rise . worsen and terminal voltage will rise. improve but terminal voltage will fall. worsen and terminal voltage will fall improve and terminal voltage will rise . worsen and terminal voltage will rise. improve but terminal voltage will fall. worsen and terminal voltage will fall ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a single phase transformer the magnitude of leakage reactance is twice that of resistance of both primary and secondary. With secondary short circuited, the input power factor is 1/√5 1/√2 1/3 2/√5 1/√5 1/√2 1/3 2/√5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 40 A. 44 A. 400 A. 440 A. 40 A. 44 A. 400 A. 440 A. ANSWER DOWNLOAD EXAMIANS APP
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