Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. presence of commutator. armature reaction. reactance voltage. high resistance of carbon brushes. presence of commutator. armature reaction. reactance voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hysteresis loss is proportional to f1.5. f. f3. f2. f1.5. f. f3. f2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The 3 - Φ induction motors are, by a very considerable margin, the most widely used AC motors as they have very good speed regulation. they are capable of operation under range of leading and lagging pf. these are cheaper in cost, simple and rugged in construction. they have maximum efficiency and maximum starting torque. they have very good speed regulation. they are capable of operation under range of leading and lagging pf. these are cheaper in cost, simple and rugged in construction. they have maximum efficiency and maximum starting torque. 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 3 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 3 are correct 1, 2 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Silicon content in steel lamination is kept within 5% as it increases hysteresis loss. All of these makes the material brittle. Increases cost. increases hysteresis loss. All of these makes the material brittle. Increases cost. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an additional resistance is connected in series with a DC motor operating at rated speed, the speed of the motor will Oscillate around the normal speed. Remain unaltered. Increase. Reduce. Oscillate around the normal speed. Remain unaltered. Increase. Reduce. ANSWER DOWNLOAD EXAMIANS APP
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