Electrical Machines In a dc machine 72 number of coils are used. Find the number of commutator segments required? 74 72 37 36 74 72 37 36 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slip of an induction motor normally does not depend on which of the following? Shaft torque. Synchronous speed. Core loss component. Rotor speed. Shaft torque. Synchronous speed. Core loss component. Rotor speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A triangular mmf wave is produced in the air gap of an electric machine. Such wave is produced by stator of a dc machine. stator of a induction machine. rotor of an synchronous machine. rotor of a dc machine. stator of a dc machine. stator of a induction machine. rotor of an synchronous machine. rotor of a dc machine. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 78.5% 82.5% 67.5% 72.5% 78.5% 82.5% 67.5% 72.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The use of higher flux density in the transformer design has no relation with the weight of transformer None of these reduces the weigh per KVA increases the weigh per KVA has no relation with the weight of transformer None of these reduces the weigh per KVA increases the weigh per KVA 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, 3 1, 2, 3 and 4 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 3 only ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS