Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. presence of commutator. reactance voltage. armature reaction. high resistance of carbon brushes. presence of commutator. reactance voltage. armature reaction. 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 2 .1 Ω 3.1 Ω 1.8 9 Ω 1.79 Ω 2 .1 Ω 3.1 Ω 1.8 9 Ω 1.79 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 V DC generator in run at rated speed with no excitation. The open circuit voltage will be zero. about 100 V. 250 V. very small, say about 2 or 3 V. zero. about 100 V. 250 V. very small, say about 2 or 3 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running at rated speed without any additional resistance in series. If an additional resistance is placedin series, the speed of motor Remains unchanged. Decreases. Increases. Oscillates around the rated speed. Remains unchanged. Decreases. Increases. Oscillates around the rated speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Shunt Motor the speed can be increased by Increasing the field current. Decreasing the field current. Increasing the field current. Increasing the armature current. Increasing the field current. Decreasing the field current. Increasing the field current. Increasing the armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In double cage induction motor, the outer cage offers low resistance and high reactance. high resistance and low reactance. low resistance and low reactance. high resistance and high reactance. low resistance and high reactance. high resistance and low reactance. low resistance and low reactance. high resistance and high reactance. ANSWER DOWNLOAD EXAMIANS APP
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