Electrical Machines In Ward-Leonard method of speed control, the direction of rotation of motor is reversed usually reversing the connection of the motor armature terminal. motor field terminal. generator armature terminal. generator field terminal. motor armature terminal. motor field terminal. generator armature terminal. generator field terminal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 3, 4, 5 2, 4, 5, 6 1, 2, 5 2, 3, 6 3, 4, 5 2, 4, 5, 6 1, 2, 5 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the brushes remain in contact with conductors which lie under north pole. lie in the inter polar gaps. lie under south pole. there is no hard and fast rule for this. lie under north pole. lie in the inter polar gaps. lie under south pole. there is no hard and fast rule for this. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Any where between 75 % and 90 %. Less than 50 % Around 90 % Around 100 %. Any where between 75 % and 90 %. Less than 50 % Around 90 % Around 100 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If any two leads from slip rings are interchanged in a 3 - Φ induction motor, the motor will get damaged. continue running in the same direction as before. run in a direction opposite to previous one. not run. get damaged. continue running in the same direction as before. run in a direction opposite to previous one. not run. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS