Electrical Machines What is power factor of a 3 - φ induction motor at no load? Equal to 1. Same as full load. Low. High. Equal to 1. Same as full load. Low. High. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutator pitches of duplex and simplex lap windings are respectively 2 and 2 2 and 1 4 ang 1 4 and 2 2 and 2 2 and 1 4 ang 1 4 and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines From no load to full load the slip will not change. None of these slightly increase. slightly decrease. not change. None of these slightly increase. slightly decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mmf produced by rotor currents of a 3 - Φ induction motor is at standstill with respect to stator mmf. rotates at the speed of rotor in the air gap. rotates at synchronous speed with respect to rotor. rotates at slip speed with respect to stator mmf. is at standstill with respect to stator mmf. rotates at the speed of rotor in the air gap. rotates at synchronous speed with respect to rotor. rotates at slip speed with respect to stator mmf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 4, 6 1, 2, 5 1, 2, 6 1, 3, 5 1, 4, 6 1, 2, 5 1, 2, 6 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
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