Electrical Machines A DC motor with armature resistance of 0.5 ohms is connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 250 A. 460 A. 570 A. 340 A. 250 A. 460 A. 570 A. 340 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 1.79 Ω 1.8 9 Ω 2 .1 Ω 3.1 Ω 1.79 Ω 1.8 9 Ω 2 .1 Ω 3.1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The ventilating ducts in most of DC machine are longitudinal. none of these. radial. radial as well as longitudinal. longitudinal. none of these. radial. radial as well as longitudinal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An 8 pole DC generator has 500 armature conductors and useful flux per pole of 0.065 Wb. What will be the emf generated if it is lap connected and runs at 1000 rpm. What must be the speed at which it is driven to produce the same emf if it is wave wound? 541.67V, 250 rpm. 2166.67V, 270 rpm. 2166.67V, 230 rpm. 541.67V, 200 rpm. 541.67V, 250 rpm. 2166.67V, 270 rpm. 2166.67V, 230 rpm. 541.67V, 200 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3-phase induction motor, torque and supply voltage are related as T ∝ 1/V T∝ V² T ∝ V T ∝ 1/V² T ∝ 1/V T∝ V² T ∝ V T ∝ 1/V² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? They are self lubricating in nature They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes All of these They are self lubricating in nature They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes All of these ANSWER DOWNLOAD EXAMIANS APP
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