Electrical Machines A 3 - Φ, 400 / 200 V, Y - Y connected wound rotor induction motor has 0.06 Ω rotor resistance and 0.3 Ω standstill reactance per phase. To make the starting torque equal to maximum torque of the motor the additional resistance required 0.78 Ω. 0.66 Ω. 0.24 Ω. 0.45 Ω. 0.78 Ω. 0.66 Ω. 0.24 Ω. 0.45 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The heat transfer by convection in a transformer least depends on surface area. air velocity. color of the paint. temperature difference. surface area. air velocity. color of the paint. temperature difference. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of residual magnetism. permanent magnets. armature reaction. None of these residual magnetism. permanent magnets. armature reaction. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the reason for stationary armature essential in alternators above 5 KVA? Operating cost is less. Insulation requirement is less. Collecting of large current is simple. All of these Operating cost is less. Insulation requirement is less. Collecting of large current is simple. All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an additional resistance is connected in series with a DC motor operating at rated speed, the speed of the motor will Increase. Oscillate around the normal speed. Reduce. Remain unaltered. Increase. Oscillate around the normal speed. Reduce. Remain unaltered. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the number of poles required, when the frequency is 50Hz and speed of the motor is 500 rpm? 12 10 24 5 12 10 24 5 ANSWER DOWNLOAD EXAMIANS APP
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