Electrical Machines The brushes of a DC machine should be placed on the commutator in the polar axis. armature in the polar axis. commutator in the inter polar axis. armature midway between poles. commutator in the polar axis. armature in the polar axis. commutator in the inter polar axis. armature midway between poles. 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 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single-winding single-phase motor has starting torque equal to full-load torque. high starting torque. zero starting torque. low starting torque. starting torque equal to full-load torque. high starting torque. zero starting torque. low starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ratio of starting torque to full load torque is minimum in Series motor. Shunt motor. Cumulative compound motor. Differential compound motor. Series motor. Shunt motor. Cumulative compound motor. Differential compound motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The field system of an alternator is usually excited 250 / 250 V DC. 230 V AC. 3 - Φ, 50 Hz and 400 V. 110 / 220 V AC. 250 / 250 V DC. 230 V AC. 3 - Φ, 50 Hz and 400 V. 110 / 220 V AC. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC motor, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve and the speed rises. deteriorate and the speed falls. improve and the speed falls. deteriorate and the speed rises. improve and the speed rises. deteriorate and the speed falls. improve and the speed falls. deteriorate and the speed rises. ANSWER DOWNLOAD EXAMIANS APP
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