Electrical Machines Ward Leonard control is provides speed control Below rated speed. In both direction. In one direction only. Above rated speed. Below rated speed. In both direction. In one direction only. Above rated speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 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 efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 72.5% 78.5% 82.5% 67.5% 72.5% 78.5% 82.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature coil is short circuited by brushes when it lies along field axis. in any of above positions. in none of above positions. along neutral axis. along field axis. in any of above positions. in none of above positions. along neutral axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V dc machine has an armature resistance of 1Ω.If the full-load current is 20 A, the differenc in the induced voltages when the machine is running as a motor and as a generator is 50 V zero 20 V 40 V 50 V zero 20 V 40 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. Find the speed of stator magnetic field with respect to rotor? zero 30 rpm 1500 rpm 1470 rpm zero 30 rpm 1500 rpm 1470 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of following methods are suitable for the speed control of squirrel cage induction motor? 1. Voltage control. 2. Frequency control. 3. Pole changing method. 4. Rotor resistance control select the correct answer using the codes given below:- 1, 3 and 4. 2, 3 and 4. 2 and 4. 1, 2 and 3. 1, 3 and 4. 2, 3 and 4. 2 and 4. 1, 2 and 3. ANSWER DOWNLOAD EXAMIANS APP
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