Electrical Machines What does the use the of height flux density value in transformer design lead to? Reduced iron loss. Increase in weight/KVA. Decrease in weight/KVA. Reduced copper loss. Reduced iron loss. Increase in weight/KVA. Decrease in weight/KVA. Reduced copper loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a 3-phase induction motor operating in its stable region decreases with increase in the load torque. increases with increase in the load torque. decreases with decrease in the load torque. remains constant. decreases with increase in the load torque. increases with increase in the load torque. decreases with decrease in the load torque. remains constant. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machine armature windings are placed on rotor because of the necessity for generation of voltage. commutation. development of torque. electromechanical energy conversion. generation of voltage. commutation. development of torque. electromechanical energy conversion. 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 1, 2, 5 3, 4, 5 2, 4, 5, 6 2, 3, 6 1, 2, 5 3, 4, 5 2, 4, 5, 6 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The demagnetising component of armature reaction in a DC generator increases armature speed. reduces inter poles flux density. reduces generator emf. results in sparking trouble. increases armature speed. reduces inter poles flux density. reduces generator emf. results in sparking trouble. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two dc machines A and B, using the same conductor material, have armature circuit resistances of 0.4 Ω and 1.2 Ω respectively. Of the two machines, A is bigger than B for the same voltage rating A is bigger than B for the same current rating both are of the same size for the same current rating B is bigger than A for the same current rating A is bigger than B for the same voltage rating A is bigger than B for the same current rating both are of the same size for the same current rating B is bigger than A for the same current rating ANSWER DOWNLOAD EXAMIANS APP