Electrical Machines A 3 - Φ, 4 pole, 50 Hz induction motor 4 % slip, calculate frequency of the rotor emf? 10 Hz. 50 Hz. 3 Hz. 2 Hz. 10 Hz. 50 Hz. 3 Hz. 2 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Thin laminations are used in a machine in order to reduce Copper losses Both 1 and 2 Hysteresis losses Eddy current losses Copper losses Both 1 and 2 Hysteresis losses Eddy current losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 2 and 3 1 alone 1 and 2 1 and 3 2 and 3 1 alone 1 and 2 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In Ward-Leonard method of speed control, the direction of rotation of motor is reversed usually reversing the connection of the generator field terminal. motor field terminal. motor armature terminal. generator armature terminal. generator field terminal. motor field terminal. motor armature terminal. generator armature terminal. 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, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running at rated speed without any additional resistance in series. If an additional resistance is placedin series, the speed of motor Oscillates around the rated speed. Remains unchanged. Decreases. Increases. Oscillates around the rated speed. Remains unchanged. Decreases. Increases. ANSWER DOWNLOAD EXAMIANS APP