Electrical Machines A generator may loose residual magnetism due to any of these. heating. vibrations. over excitation. any of these. heating. vibrations. over excitation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when none of above. back emf is equal to half of applied voltage. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. none of above. back emf is equal to half of applied voltage. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous machine has P number of poles, find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm)? ωe = P/2*ωm ωe = ωm ωe = P*ωm ωe = 2/P*ωm ωe = P/2*ωm ωe = ωm ωe = P*ωm ωe = 2/P*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following statement is correct, if short circuit ratio is high? Good voltage regulation High voltage regulation None of these Low short circuit current Good voltage regulation High voltage regulation None of these Low short circuit current ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generator, which component plays the vital role to produce the direct current? Brush. Commutator. Yoke. Armature. Brush. Commutator. Yoke. Armature. 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