Electrical Machines Which of the following DC generators has rising V-I characteristics? Compound. None of them. Series. Shunt. Compound. None of them. Series. Shunt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When excitation is increased (over excitation), the synchronous generator operates at lagging power factor. leading power factor. any of the above. unity power factor. lagging power factor. leading power factor. any of the above. unity power factor. 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 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 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 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 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a motor falls from 1100 r.p.m at no-load to 1050 r.p.m at rated load. The speed regulation of motor is 3.76%. 2.57 %. 2.56 %. 4.76%. 3.76%. 2.57 %. 2.56 %. 4.76%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 920 RPM 970 RPM 940 RPM 960 RPM 920 RPM 970 RPM 940 RPM 960 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 500 V, 55 kVA single phase alternator has an effective resistance of 0.5 Ω. An excitation current of 10 A produces 200 A armature current on short circuit and an emf of 450 V on per circuit. The synchronous reactance will be 2.74 Ω. 25.564 Ω. 2.241 Ω. 2.781 Ω. 2.74 Ω. 25.564 Ω. 2.241 Ω. 2.781 Ω. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS