Electrical Machines What is the phase difference between two windings of A.C servomotor ? 30°. 60°. 90°. 120°. 30°. 60°. 90°. 120°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a stepper motor the detente torque means maximum of the static torque with the phase winding excited. minimum of the static torque with the phase winding unexcited. minimum of the static torque with the phase winding excited. maximum of the static torque with the phase winding unexcited. maximum of the static torque with the phase winding excited. minimum of the static torque with the phase winding unexcited. minimum of the static torque with the phase winding excited. maximum of the static torque with the phase winding unexcited. 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, 2 and 3 3 only 1, 2, 3 and 4 1, 3 1, 2 and 3 3 only 1, 2, 3 and 4 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC machine is made of silicon steel lamination to reduce eddy current loss only. reduce both eddy current and hysteresis loss. reduce hysteresis loss only. increase the permeability. reduce eddy current loss only. reduce both eddy current and hysteresis loss. reduce hysteresis loss only. increase the permeability. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase slip-ring induction motor, brushes are connected to DC supply. 3 - Φ AC supply. equalizing coils. external star-connected resistors. DC supply. 3 - Φ AC supply. equalizing coils. external star-connected resistors. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 500 V, 55 kVA single phase alternator has an effective resistance of 0.5 Ω. An excitation current of 10 A produces 200 A armature current on short circuit and an emf of 450 V on per circuit. The synchronous reactance will be 2.241 Ω. 2.74 Ω. 2.781 Ω. 25.564 Ω. 2.241 Ω. 2.74 Ω. 2.781 Ω. 25.564 Ω. ANSWER DOWNLOAD EXAMIANS APP
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