Electrical Machines When R2 is rotor resistance, X2 the rotor reactance at supply frequency and s the slip, then the condition for maximum torque under running condition will be R2 = sX2. sR2 = X2. R2 = s2X2. R2 = s2X2. R2 = sX2. sR2 = X2. R2 = s2X2. R2 = s2X2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 2, 3 , 5 1, 4 1, 3, 5 2, 4 ,5 2, 3 , 5 1, 4 1, 3, 5 2, 4 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The principle of operation of a 3 - Φ induction motor is almost similar to that of transformer with secondary short circuited. synchronous motor. capacitor start induction motor. repulsion start induction motor. transformer with secondary short circuited. synchronous motor. capacitor start induction motor. repulsion start induction motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The flux involved in the emf equation of a transformer has total value. average value. maximum value. rms value. total value. average value. maximum value. rms value. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC generator will not build up voltage due to wrong direction of rotation. if field resistance is more than critical resistance. if it has lost residual magnetism. any one of above. due to wrong direction of rotation. if field resistance is more than critical resistance. if it has lost residual magnetism. any one of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sequence of induction motor is RYB, then the direction of induction motor can be changed by which of the following sequence? BRY RBY BYR All of these BRY RBY BYR All of these ANSWER DOWNLOAD EXAMIANS APP
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