Electrical Machines What is the highest possible speed of turbo alternators? 1500 rpm 3000 rpm 1000 rpm 4000 rpm 1500 rpm 3000 rpm 1000 rpm 4000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For higher values of armature, the speed of a DC series motor is Inversely proportional to armature current. Constant. Proportional to armature current. Proportional to the square of armature current. Inversely proportional to armature current. Constant. Proportional to armature current. Proportional to the square of armature current. 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, 4, 5 1, 2, 3 2, 3 ,5 2, 3, 4 2, 3, 4, 5 1, 2, 3 2, 3 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Eb/V ratio of a DC motor is an indication of Speed regulation. Starting torque. Effiency. Running Torque. Speed regulation. Starting torque. Effiency. Running Torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, which of these parameters remain the same whether it runs as a DC motor or a DC generator? Armature current. Induced emf. Can not be determined. Mechanical power. Armature current. Induced emf. Can not be determined. Mechanical power. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc generator operating on load with its brushes on the geometrical neutral axis (GNA), the magnetic neutral axis (MNA) is shifted in the direction of rotation. Now, if the brushes are given a lead of 90° (electrical), then the MNA will shift forward by 90° shift forward by more than 90° coincide with the GNA shift forward by less than 90° shift forward by 90° shift forward by more than 90° coincide with the GNA shift forward by less than 90° ANSWER DOWNLOAD EXAMIANS APP