Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 50 Hz. 16.67 Hz. 25 Hz. 60 Hz. 50 Hz. 16.67 Hz. 25 Hz. 60 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In normal dc machines operating at full-load conditions, the most powerful electromagnet is armature winding interpole winding interpole and compensating windings together field winding armature winding interpole winding interpole and compensating windings together field winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The compensating winding in a DC machine is located on pole shoes to avoid the sparking at the brushes. is located on pole shoes for avoiding the flashover at the commutator. is located in armature slots for compensation of the armature reaction. is located on commutating poles for improving commutation. is located on pole shoes to avoid the sparking at the brushes. is located on pole shoes for avoiding the flashover at the commutator. is located in armature slots for compensation of the armature reaction. is located on commutating poles for improving commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In most condition which frame of motor will be preferred? Open type. Splash proof. Totally enclosed fan coiled. Drip proof. Open type. Splash proof. Totally enclosed fan coiled. Drip proof. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous motor is supplying a load at unity power factor. If the load on the motor is increased keeping its excitation and terminal voltage constant, the power factor will remain the same will become lagging will become leading None of these will remain the same will become lagging will become leading None of these ANSWER DOWNLOAD EXAMIANS APP
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