Electrical Machines If the back emf in DC motor vanishes suddenly the motor will run at very high speed. run at very low speed. burn. start haunting. run at very high speed. run at very low speed. burn. start haunting. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Over-excitation. Periodic variation of load. Over-loading for long period. Small and constant load. Over-excitation. Periodic variation of load. Over-loading for long period. Small and constant load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5Ω and back back emf 200 V is 400 A. 440 A. 44 A. 40 A. 400 A. 440 A. 44 A. 40 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by shifting the brush axis from GNA to MNA. fixing the brush axis inline with the pole axis. increasing field excitation. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. fixing the brush axis inline with the pole axis. increasing field excitation. compensating winding and commutating poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, the angle between the stator and rotor fields is 0o. 90o. dependent upon the load. 180o. 0o. 90o. dependent upon the load. 180o. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A bipolar dc machine with interpoles has a main-pole flux of ф per pole and an interpole flux of Фᵢ per pole. The yoke of the machine is devide into four quadrants by the main-pole axis and The commutation axis. The flux-distribution in the quadrants will be ½ ( ф + фᵢ ) in two adjacent quadrants and ½ ( ф - фᵢ ) in the remaining two quadrants ½ ( ф + фᵢ ) in two diametrically opposite quadrants and ½ ( ф - фᵢ ) in the remaining two Quadrants ½ ( ф + фᵢ ) in all the four quadrants ½ ( ф - фᵢ ) in all the four quadrants ½ ( ф + фᵢ ) in two adjacent quadrants and ½ ( ф - фᵢ ) in the remaining two quadrants ½ ( ф + фᵢ ) in two diametrically opposite quadrants and ½ ( ф - фᵢ ) in the remaining two Quadrants ½ ( ф + фᵢ ) in all the four quadrants ½ ( ф - фᵢ ) in all the four quadrants ANSWER DOWNLOAD EXAMIANS APP
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