Electrical Machines The speed of rotating magnetic field of 8 pole 50 Hz induction motor is 1500 rpm 750 rpm 3000 rpm 1000 rpm 1500 rpm 750 rpm 3000 rpm 1000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 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 0.95 1.06 0.87 0.96 0.95 1.06 0.87 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC shunt motor if load is reduced The speed will increase abruptly. The speed will remains almost constant. The speed will increase in proportion to reduction in load. DC Shunt Motor The speed will increase abruptly. The speed will remains almost constant. The speed will increase in proportion to reduction in load. DC Shunt Motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Winding conductors of an electrical power transformer are mainly insulated by cotton insulation. wooden insulation. rubber insulation. paper insulation. cotton insulation. wooden insulation. rubber insulation. paper insulation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC cumulatively compounded motor delivers rated load torque at rated speed. If the series field is short-circuited, then the armature current and speed will both increase increase and decrease respectively decrease and increase respectively both decrease both increase increase and decrease respectively decrease and increase respectively both decrease ANSWER DOWNLOAD EXAMIANS APP