Electrical Machines The no load current in a transformer lags the applied voltage by 0°. 90°. about 75°. about 115°. 0°. 90°. about 75°. about 115°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field circuit of a DC shunt motor is opened The motor will attain dangerously high speed. The armature current will reduce. The speed of motor will be reduced. DC Shunt Motor The motor will attain dangerously high speed. The armature current will reduce. The speed of motor will be reduced. DC Shunt Motor 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%. 970 RPM 920 RPM 940 RPM 960 RPM 970 RPM 920 RPM 940 RPM 960 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the frequency of rotor current of 50 Hz induction motor operating at 4% slip? 2.5Hz 1 Hz 50Hz 2HZ 2.5Hz 1 Hz 50Hz 2HZ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an AC servomotor has one of its winding excited by AC, then voltage measured at the other winding with rotor running will be proportional to square of rotor speed. zero. constant independent of speed. proportional to rotor speed. proportional to square of rotor speed. zero. constant independent of speed. proportional to rotor speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The fall in speed of the DC generator due to increase in load can be corrected by reducing the load voltage. increasing the excitation. increasing the input to the prime mover. cooling the armature. reducing the load voltage. increasing the excitation. increasing the input to the prime mover. cooling the armature. ANSWER DOWNLOAD EXAMIANS APP