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 ? 230 V. 150 V. 240 V. 210 V 230 V. 150 V. 240 V. 210 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, electric current to the external circuit from armature is given through commutator. slip rings. solid connection. none of above. commutator. slip rings. solid connection. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Oil is provided in an oil filled transformer for insulating. cooling. both cooling and insulation. lubrication. insulating. cooling. both cooling and insulation. lubrication. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the magnetization characteristics of a dc generator : 1. It represents the variation of field flux with field current. 2. Variation of open-circuit terminal voltage with field current is independent of speed 3. It is non-linear from zero to rated field current 4. It helps to determine the critical field resistance at a given speed 5. It always starts from the origin Which of these statements are correct ? 2, 3 and 4 3 and 5 1, 2 and 5 1 and 4 2, 3 and 4 3 and 5 1, 2 and 5 1 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the armature windings are placed on the rotor because of the necessity for commutation generation of voltage development of torque electromechanical energy conversion commutation generation of voltage development of torque electromechanical energy conversion ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a seperately excited DC Motor if field current is increased, it will Reduce armature heating. Increase acceleration duration. Reduce starting torque. Increase speed Reduce armature heating. Increase acceleration duration. Reduce starting torque. Increase speed ANSWER DOWNLOAD EXAMIANS APP
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