Electrical Machines As compared to an induction motor, the air gap in a DC motor is same. less than 50%. more. between 50% and 90%. same. less than 50%. more. between 50% and 90%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes increase in speed demanding more armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed demanding more armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field current is reduced to zero the maximum power developed by alternator is 2.73 KW. 1.644 KW. 5.46 KW. 0.9103 KW. 2.73 KW. 1.644 KW. 5.46 KW. 0.9103 KW. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 1, 4 2, 3 , 5 2, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The synchronous reactance( Xs) is the reactance due to leakage flux combined reactance due to armature reaction and leakage flux reactance either due to armature reaction or leakage flux reactance due to armature reaction of the machine reactance due to leakage flux combined reactance due to armature reaction and leakage flux reactance either due to armature reaction or leakage flux reactance due to armature reaction of the machine 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 4 X 1012 Ω - cm at 27°C and 0.4 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 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 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 ANSWER DOWNLOAD EXAMIANS APP