Electrical Machines A 4-pole dc generator runs at 1500 rpm. The frequencyof current in the armature winding is 50 Hz 0 Hz 100 Hz 25 Hz 50 Hz 0 Hz 100 Hz 25 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 400 / 200 V, Y - Y connected wound rotor induction motor has 0.06 Ω rotor resistance and 0.3 Ω standstill reactance per phase. To make the starting torque equal to maximum torque of the motor the additional resistance required 0.78 Ω. 0.24 Ω. 0.45 Ω. 0.66 Ω. 0.78 Ω. 0.24 Ω. 0.45 Ω. 0.66 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then E ∝ 1/(φf) E ∝ φf E ∝ φ/f E ∝ f/φ E ∝ 1/(φf) E ∝ φf E ∝ φ/f E ∝ f/φ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutators in DC machines have a role of which converts high voltage DC to low voltage DC. none of these. Both AC to DC and DC to AC. AC to DC. high voltage DC to low voltage DC. none of these. Both AC to DC and DC to AC. AC to DC. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ induction motor power factor at starting is low as compared to that while running. power factor at starting in the same as that while running. none of them. power factor at starting is high as compared to that while running. power factor at starting is low as compared to that while running. power factor at starting in the same as that while running. none of them. power factor at starting is high as compared to that while running. 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%. 940 RPM 920 RPM 960 RPM 970 RPM 940 RPM 920 RPM 960 RPM 970 RPM ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS