Electrical Machines Autotransformer makes effective saving on copper and copper losses, when its transformation ratio is equal to approx to one. very low less than one. greater than one. approx to one. very low less than one. greater than one. ANSWER DOWNLOAD EXAMIANS APP
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 ∝ f/φ E ∝ φ/f E ∝ φf E ∝ 1/(φf) E ∝ f/φ E ∝ φ/f E ∝ φf E ∝ 1/(φf) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sparking at the the brushes, in a DC machines is due to armature reaction. reactance voltage. high resistance of carbon brushes. presence of commutator. armature reaction. reactance voltage. high resistance of carbon brushes. presence of commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. The frequency of rotor current is 0 Hz 1 Hz 5 Hz 50 Hz 0 Hz 1 Hz 5 Hz 50 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor electromagnetic torque developed is Proportional to the square of armature current. Inversely proportional to the armature current. Proportional to the armature current. None of above. Proportional to the square of armature current. Inversely proportional to the armature current. Proportional to the armature current. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slip of an induction motor normally does not depend on which of the following? Rotor speed. Synchronous speed. Core loss component. Shaft torque. Rotor speed. Synchronous speed. Core loss component. Shaft torque. ANSWER DOWNLOAD EXAMIANS APP
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