Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to applied voltage. back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. none of above. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Unity power factor. Zero power factor. Lagging power factor. Leading power factor. Unity power factor. Zero power factor. Lagging power factor. Leading power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor wound rotor motor is mainly is used in application where high starting torque. low starting torque. power factor is less. less costly motor is not required. high starting torque. low starting torque. power factor is less. less costly motor is not required. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the commutator pitch? Number of commutator segments between two successive coils. Number of conductors spanned by one coil at the back end of the armature. Number of conductors spanned by one coil at the front end of the armature. The distance between the staring of first coil and its next successive coil Number of commutator segments between two successive coils. Number of conductors spanned by one coil at the back end of the armature. Number of conductors spanned by one coil at the front end of the armature. The distance between the staring of first coil and its next successive coil ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an additional resistance is connected in series with a DC series motor operating at rated speed, the speed of the motor will Reduce. Increase. Oscillate around the normal speed. Remain unaltered. Reduce. Increase. Oscillate around the normal speed. Remain unaltered. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the back emf in DC motor vanishes suddenly the motor will burn. run at very low speed. start haunting. run at very high speed. burn. run at very low speed. start haunting. run at very high speed. ANSWER DOWNLOAD EXAMIANS APP
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