Electrical Machines In a 3-phase induction motor, if the supply voltage and frequency are reduced by the same ratio, then slip at which maximum torque occurs is more and maximum torque decreases less and maximum torque increases more and maximum torque remains constant less and maximum torque decreases more and maximum torque decreases less and maximum torque increases more and maximum torque remains constant less and maximum torque decreases ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Zero power factor. Lagging power factor. Unity power factor. Leading power factor. Zero power factor. Lagging power factor. Unity power factor. Leading power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are not a self starting motor? None of these both 1 and 2 1-phase induction motor 3-phase induction motor None of these both 1 and 2 1-phase induction motor 3-phase induction motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 4 pole IM is supplied from a 50 Hz source. Calculate rotor frequency when rotor runs 600 rpm? 30 Hz. 20 Hz. 35 Hz. Can be determined. 30 Hz. 20 Hz. 35 Hz. Can be determined. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed demanding more armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed demanding more armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 3 1, 4 2, 4 1, 3 2, 3 1, 4 2, 4 1, 3 ANSWER DOWNLOAD EXAMIANS APP
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