Electrical Machines For a 3 - Φ, 4 pole, 50 Hz IM rotating at full load speed of 1440 rpm, calculate speed of rotor field with respect to rotor structure and stator structure respectively? 1440, 1500. 60, 1440. 60, 1500. 50, 1500. 1440, 1500. 60, 1440. 60, 1500. 50, 1500. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.96 1.06 0.95 0.87 0.96 1.06 0.95 0.87 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods are used to control the speed of DC motors is All of these supply voltage control field current control armature circuit resistance control All of these supply voltage control field current control armature circuit resistance control ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited DC generator, running at rated speed, has 6 volts across its armature terminals with no field current. When field winding is excited with one ampere, the voltage builds up to 250 V at no load. In case field current is reduced to zero, with the speed remaining unaltered, the armature terminal voltage would be zero 6 V more than 6 V less than 6 V zero 6 V more than 6 V less than 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The ventilating ducts in most of DC machine are radial. radial as well as longitudinal. none of these. longitudinal. radial. radial as well as longitudinal. none of these. longitudinal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 2, 3 and 5 1, 3 and 5 1 and 3 1, 2 and 3 1, 2, 3 and 5 1, 3 and 5 1 and 3 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS