Electrical Machines The field system of an alternator is usually excited 250 / 250 V DC. 3 - Φ, 50 Hz and 400 V. 230 V AC. 110 / 220 V AC. 250 / 250 V DC. 3 - Φ, 50 Hz and 400 V. 230 V AC. 110 / 220 V AC. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1, 2, and 3 1, 2 and 4 2, 3 and 4 1 and 3 1, 2, and 3 1, 2 and 4 2, 3 and 4 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V DC machine has an armature resistance 1Ω. If the full load current is 20 A, the difference of induced voltage and generator is 0 V. 60 V. 40 V. 20 V. 0 V. 60 V. 40 V. 20 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If a DC Series motor is connected across an AC supply it will burn. not run. run at normal speed. run at lower speed. burn. not run. run at normal speed. run at lower speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 6 pole, 50 Hz IM is running at a full load speed of 980 rpm. If it delivers an air gap power of 98000 Watt, calculate the rotor ohmic loss? 1920 Watt. 1800 Watt. 980 Watt. 1960 Watt. 1920 Watt. 1800 Watt. 980 Watt. 1960 Watt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a stepper motor the detente torque means minimum of the static torque with the phase winding unexcited. maximum of the static torque with the phase winding excited. maximum of the static torque with the phase winding unexcited. minimum of the static torque with the phase winding excited. minimum of the static torque with the phase winding unexcited. maximum of the static torque with the phase winding excited. maximum of the static torque with the phase winding unexcited. minimum of the static torque with the phase winding excited. ANSWER DOWNLOAD EXAMIANS APP
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