Electrical Machines The interpoles in dc machines have a tapering shape in order to increase the acceleration of commutation reduce the overall weight economise on the material required for interpoles and their windings reduce the saturation in the interpole increase the acceleration of commutation reduce the overall weight economise on the material required for interpoles and their windings reduce the saturation in the interpole ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2 A armature current at no-load, when the armature current is changed to 20 A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 4575.4 r.p.m. 1130 r.p.m. 1037.5 r.p.m. none of above. 4575.4 r.p.m. 1130 r.p.m. 1037.5 r.p.m. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 8 Ω. 4 Ω. 10 Ω. 2 Ω. 8 Ω. 4 Ω. 10 Ω. 2 Ω. 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 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a induction motor helps to increase the starting torque. reduce the magnetizing current. reduce the chance of cogging. reduce the chance of crawling. increase the starting torque. reduce the magnetizing current. reduce the chance of cogging. reduce the chance of crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What does the use the of height flux density value in transformer design lead to? Increase in weight/KVA. Reduced iron loss. Reduced copper loss. Decrease in weight/KVA. Increase in weight/KVA. Reduced iron loss. Reduced copper loss. Decrease in weight/KVA. ANSWER DOWNLOAD EXAMIANS APP
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