Electrical Machines An induction motor has a rotor resistance of 0.002 Ω / phase. If the resistance is increased to 0.004 Ω / phase then the maximum torque will reduced to half increase by 100% remain unaltered increase by 200% reduced to half increase by 100% remain unaltered increase by 200% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature shaft must be able to withstand All of these any unbalanced magnetic pull on the armature core. twisting strains due to transmission of torque. bending moment due to weight of the armature. All of these any unbalanced magnetic pull on the armature core. twisting strains due to transmission of torque. bending moment due to weight of the armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor slots are slightly skewed in squirrel cage induction motor to provide ease of fabrication. increase the strength of rotor bars. decrease the amount of copper to be used. reduce the magnetic hum and locking tendency of rotor. provide ease of fabrication. increase the strength of rotor bars. decrease the amount of copper to be used. reduce the magnetic hum and locking tendency of rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 4 pole, 50 Hz induction motor 4 % slip, calculate frequency of the rotor emf? 3 Hz. 50 Hz. 10 Hz. 2 Hz. 3 Hz. 50 Hz. 10 Hz. 2 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 4 1, 3 2, 3 1, 4 2, 4 1, 3 2, 3 1, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Wave winding is prefered for which of the following rating? high current and low voltage low current and low voltage low current and high voltage high current and high voltage high current and low voltage low current and low voltage low current and high voltage high current and high voltage ANSWER DOWNLOAD EXAMIANS APP