Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 440 A. 40 A. 44 A. 400 A. 440 A. 40 A. 44 A. 400 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuiting is caused in the armature winding due to any of above. failure of insulation between two commutator bars. grounding of two or more turns of the same coil. failure of insulation between two turns of coil. any of above. failure of insulation between two commutator bars. grounding of two or more turns of the same coil. failure of insulation between two turns of coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor must started on no load because it would Run at dangerously high speed. Fail to start without load. Not develop starting torque. Draw more current without producing sufficient torque. Run at dangerously high speed. Fail to start without load. Not develop starting torque. Draw more current without producing sufficient torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is ineffective. demagnetizing. cross – magnetizing. magnetizing. ineffective. demagnetizing. cross – magnetizing. magnetizing. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 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 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 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 Where the shunt generators are widely used? Where often load fluctuation is occurred. Where the load is very high. Where a constant voltage is required over a narrow load range. Where voltage variation is needed over a wide load range. Where often load fluctuation is occurred. Where the load is very high. Where a constant voltage is required over a narrow load range. Where voltage variation is needed over a wide load range. ANSWER DOWNLOAD EXAMIANS APP
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