Electrical Machines In speed control of DC shunt motor by varying field flux, what may be the value of field regulator? 2 ohm. 100 ohm 0.2 ohm 10 ohm 2 ohm. 100 ohm 0.2 ohm 10 ohm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An ideal synchronous motor has no starting torque because relative velocity between the stator and rotor mmf’s is zero. rotor is made up of salient poles. rotor winding is highly reactive. relative velocity between stator and rotor mmf’s is not zero. relative velocity between the stator and rotor mmf’s is zero. rotor is made up of salient poles. rotor winding is highly reactive. relative velocity between stator and rotor mmf’s is not zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 1, 4 1, 3, 5 2, 4 ,5 2, 3 , 5 1, 4 1, 3, 5 2, 4 ,5 2, 3 , 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machines shape of net flux density is? peaky in nature flat tapped or trapezoidal saddle shape sine wave peaky in nature flat tapped or trapezoidal saddle shape sine wave ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 970 RPM 960 RPM 940 RPM 920 RPM 970 RPM 960 RPM 940 RPM 920 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which one of the following statement is correct ? In an induction motor if the air gap is increased then its speed will reduce its efficiency will improve its power factor will reduce its speed will increase its speed will reduce its efficiency will improve its power factor will reduce its speed will increase ANSWER DOWNLOAD EXAMIANS APP
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