Electrical Machines A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.75 p.u 0.25 p.u 0.125 p.u 0.5 p.u 0.75 p.u 0.25 p.u 0.125 p.u 0.5 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator, inverted V curve is drawn between field current on X-axis and power factor on Y-axis field current on Y-axis and power factor on X-axis field current on Y-axis and armature current on X-axis field current on X-axis and armature current on Y-axis field current on X-axis and power factor on Y-axis field current on Y-axis and power factor on X-axis field current on Y-axis and armature current on X-axis field current on X-axis and armature current on Y-axis ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If any two leads from slip rings are interchanged in a 3 - Φ induction motor, the motor will get damaged. continue running in the same direction as before. not run. run in a direction opposite to previous one. get damaged. continue running in the same direction as before. not run. run in a direction opposite to previous one. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The factors that are responsible for decrease in terminal voltage of a shunt generator are armature resistance, effect of armature reaction. armature resistance, inter poles, armature. reduction in field current, effect of armature reaction, armature. armature resistance, effect of armature reaction. armature resistance, effect of armature reaction. armature resistance, inter poles, armature. reduction in field current, effect of armature reaction, armature. armature resistance, effect of armature reaction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the space waveform of the air-gap flux distribution affects voltage but not the torque torque but not the voltage neither the voltage nor the torque both the torque and voltage voltage but not the torque torque but not the voltage neither the voltage nor the torque both the torque and voltage ANSWER DOWNLOAD EXAMIANS APP