Electrical Machines A single-phase transformer has its maximum efficiency at 60 percent of full load. At full load copper loss will be more than core loss. less than core loss. equal to core loss. zero. more than core loss. less than core loss. equal to core loss. zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 2, 3, 4 2, 3 ,5 2, 3, 4, 5 1, 2, 3 2, 3, 4 2, 3 ,5 2, 3, 4, 5 1, 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutation in a DC machine may be explained as a process by which electric current in a coil is reversed. by virtue of which emf is induced in the armature conductors. in which magnetic field is set up. how alternate flux affects the main field flux. by which electric current in a coil is reversed. by virtue of which emf is induced in the armature conductors. in which magnetic field is set up. how alternate flux affects the main field flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generator, armature reaction refers to what? Effect of field flux on the armature flux. Effect of armature flux on the main field flux. Effect of armature flux on the load. None of these Effect of field flux on the armature flux. Effect of armature flux on the main field flux. Effect of armature flux on the load. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a dc motor the ratio Eb / E is indicative of ratio of input to output voltage. ratio of starting to running current. ratio of starting to running torque. efficiency. ratio of input to output voltage. ratio of starting to running current. ratio of starting to running torque. efficiency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the armature windings are placed on the rotor because of the necessity for generation of voltage commutation electromechanical energy conversion development of torque generation of voltage commutation electromechanical energy conversion development of torque ANSWER DOWNLOAD EXAMIANS APP