Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 2 at 90°C. 3 at 90°C. 1 at 90°C. 0.5 at 90°C. 2 at 90°C. 3 at 90°C. 1 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1000 1200 1203 1080 1000 1200 1203 1080 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V dc machine has an armature resistance of 1Ω.If the full-load current is 20 A, the differenc in the induced voltages when the machine is running as a motor and as a generator is 50 V 40 V zero 20 V 50 V 40 V zero 20 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing divertor resistance of a DC series motor Increase in speed but armature currnet remains the same. Increase in speed demanding more armature current. Decrease in speed demanding less armature current. Decrease in speed but armature current remains the same. Increase in speed but armature currnet remains the same. Increase in speed demanding more armature current. Decrease in speed demanding less armature current. Decrease in speed but armature current remains the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the residual magnetism is of the order of 20 %. 10 %. 15 %. 2.5 %. 20 %. 10 %. 15 %. 2.5 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Mechanical energy is supplied to DC generator at the rate of 4200 J / s. The generator delivers 32.2 Amp at 120 V. What is the percentage efficiency of the generator? 205 V. 210 V. 212 V. 201.02 V. 205 V. 210 V. 212 V. 201.02 V. ANSWER DOWNLOAD EXAMIANS APP
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