Electrical Machines The power factor of an induction motor operating at no load will have a value around 0.2 lag 0.9 lag unity 0.2 lead 0.2 lag 0.9 lag unity 0.2 lead ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 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 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 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machine is invariably provided with forced ventilation? Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. 50 MW generator in a power plant. Fractional horse power slow speed motor. Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. 50 MW generator in a power plant. Fractional horse power slow speed motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the armature midway between poles. armature in the polar axis. commutator in the polar axis. commutator in the inter polar axis. armature midway between poles. armature in the polar axis. commutator in the polar axis. commutator in the inter polar axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC generator will not build up voltage if it has lost residual magnetism. due to wrong direction of rotation. if field resistance is more than critical resistance. any one of above. if it has lost residual magnetism. due to wrong direction of rotation. if field resistance is more than critical resistance. any one of above. ANSWER DOWNLOAD EXAMIANS APP