Electrical Machines What will happen if the the supply terminals are reversed in case of a DC shunt motor? The motor will run much faster in the same direction. The motor will run in reverse direction. The motor will run at its normal speed in the same direction as before. The motor will stop. The motor will run much faster in the same direction. The motor will run in reverse direction. The motor will run at its normal speed in the same direction as before. The motor will stop. 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, 4 ,5 2, 3 , 5 1, 3, 5 1, 4 2, 4 ,5 2, 3 , 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 74 Nm. 38.5 Nm. 65.8 Nm. 27.73 Nm . 74 Nm. 38.5 Nm. 65.8 Nm. 27.73 Nm . ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutator in DC generator is used for reduce losses increase efficiency convert AC armature current in to DC collecting of current reduce losses increase efficiency convert AC armature current in to DC collecting of current ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In applied voltage is reduced in a dc shunt motor Full load current. Full load torque. None of these. Full load speed. Full load current. Full load torque. None of these. Full load speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the residual magnetism is of the order of 10 %. 2.5 %. 15 %. 20 %. 10 %. 2.5 %. 15 %. 20 %. ANSWER DOWNLOAD EXAMIANS APP