Electrical Machines In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then E ∝ φ/f E ∝ 1/(φf) E ∝ f/φ E ∝ φf E ∝ φ/f E ∝ 1/(φf) E ∝ f/φ E ∝ φf ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For standing a DC motor a starter is required because it limits the starting current to a safe value. None of these it limits the speed of the motor. It starts the motor. it limits the starting current to a safe value. None of these it limits the speed of the motor. It starts the motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the residual magnetism is of the order of 15 %. 10 %. 2.5 %. 20 %. 15 %. 10 %. 2.5 %. 20 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is reduced, the power factor is unity power factor leading power factor lagging power factor None of these unity power factor leading power factor lagging power factor None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Sparkless commutation can be achieved by employing compensating winding. any one or more of the above methods. inter poles. high resistance carbon brushes. compensating winding. any one or more of the above methods. inter poles. high resistance carbon brushes. 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
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