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 In case of IM the torque is directly proportional to slip. inversely proportional to √slip. inversely proportional to slip. directly proportional to slip2. directly proportional to slip. inversely proportional to √slip. inversely proportional to slip. directly proportional to slip2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines It is an advisable to use auto transformer if the transformation ratio is 0.5. 0.25. near to 1. Greater than 1. 0.5. 0.25. near to 1. Greater than 1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is increased, the power factor is leading power factor unity power factor lagging power factor None of these leading power factor unity power factor lagging power factor None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the pitch factor? Cos α sin (α/2) Cos (α/2) Cos α² Cos α sin (α/2) Cos (α/2) Cos α² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Shunt Motor having shunt field resistance of 250 Ω and armature resistance of 0.5 Ω is connected to 250 V supply and load current of 21 A. What is the back emf generated ? 240 V. 150 V. 230 V. 210 V 240 V. 150 V. 230 V. 210 V ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS