Electrical Machines In dc machines, the space distribution of air-gap flux density wave at no load is rectangular flat-topped sinusoidal co- sinusoidal rectangular flat-topped sinusoidal co- sinusoidal 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 Armature coil is short circuited by brushes when it lies in none of above positions. in any of above positions. along field axis. along neutral axis. in none of above positions. in any of above positions. along field axis. along neutral axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the motor may run away. the starting torque becomes low. the starting current will be enormously high. the motor may not start. the motor may run away. the starting torque becomes low. the starting current will be enormously high. the motor may not start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The low voltage winding of a 400/230 V single phase 50 Hz transformer is to be connected to keep the magnetization current at the same level in both the cases the voltage at 25 Hz should be 115 V 230 V 460 V 65 V 115 V 230 V 460 V 65 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is not a necessary condition to be satisfied for synchronising an incoming alternator to an already operating alternator? same phase sequence same voltage magnitude same prime mover speed same frequency same phase sequence same voltage magnitude same prime mover speed same frequency ANSWER DOWNLOAD EXAMIANS APP
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