Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by s2. sf / 2. f / s. sf. s2. sf / 2. f / s. sf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of a DC motor is laminated to reduce friction and windage loss. copper loss. hysteresis loss. eddy current loss. friction and windage loss. copper loss. hysteresis loss. eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. None of these. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. None of these. To convert alternating supply current to direct current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the synchronous reactance of alternators in which a given field current of 200 A on short circuit and a generated emf of 50 V on open circuit. Armature resistance is 0.1 ohm 0.5Ω. 0.25Ω. 0.23Ω. 1Ω. 0.5Ω. 0.25Ω. 0.23Ω. 1Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What does the use the of height flux density value in transformer design lead to? Increase in weight/KVA. Reduced copper loss. Reduced iron loss. Decrease in weight/KVA. Increase in weight/KVA. Reduced copper loss. Reduced iron loss. Decrease in weight/KVA. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An IM cannot run at synchronous speed because rotor torque will not be produced. air friction will prevent it. induction motor will become synchronous motor. none of above. rotor torque will not be produced. air friction will prevent it. induction motor will become synchronous motor. none of above. ANSWER DOWNLOAD EXAMIANS APP
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