Electrical Machines The rotor slots are slightly skewed in squirrel cage induction motor to decrease the amount of copper to be used. increase the strength of rotor bars. provide ease of fabrication. reduce the magnetic hum and locking tendency of rotor. decrease the amount of copper to be used. increase the strength of rotor bars. provide ease of fabrication. reduce the magnetic hum and locking tendency of rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 2 Ω. 8 Ω. 4 Ω. 10 Ω. 2 Ω. 8 Ω. 4 Ω. 10 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flux density under trailing pole tips in case of generator will None of these either increase or decrease increase decrease None of these either increase or decrease increase decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 3 3 only 1, 2, 3 and 4 1, 2 and 3 1, 3 3 only 1, 2, 3 and 4 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Field winding of a DC series motor is usually provided with thick wire as it carries large load current. to reduce the insulation of materials. in order to reduce eddy current to provide large flux. to provide large flux. as it carries large load current. to reduce the insulation of materials. in order to reduce eddy current to provide large flux. to provide large flux. 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, 2, 5 1, 2, 6 1, 3, 5 1, 4, 6 1, 2, 5 1, 2, 6 1, 3, 5 1, 4, 6 ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS