Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. too rapid reversal of current. any of the above. over commutation. under commutation. too rapid reversal of current. any of the above. over commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What will be the maximum power factor of an induction motor for dispersion coefficient of 0.05? 1.1. 0.905. 0.05. 20. 1.1. 0.905. 0.05. 20. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC motors, under trailing pole tips, flux density will_______ ? either increase or decrease decrease None of these increase either increase or decrease decrease None of these increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 500 V, 55 kVA single phase alternator has an effective resistance of 0.5 Ω. An excitation current of 10 A produces 200 A armature current on short circuit and an emf of 450 V on per circuit. The synchronous reactance will be 25.564 Ω. 2.241 Ω. 2.74 Ω. 2.781 Ω. 25.564 Ω. 2.241 Ω. 2.74 Ω. 2.781 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the starting torque becomes low. the starting current will be enormously high. the motor may run away. the motor may not start. the starting torque becomes low. the starting current will be enormously high. the motor may run away. the motor may not start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the mechanical power is developed by a DC motor maximum Back emf is equal. back emf is equal to applied voltage. Back emf is equal to half of applied voltage. None of above. Back emf is equal. back emf is equal to applied voltage. Back emf is equal to half of applied voltage. None of above. ANSWER DOWNLOAD EXAMIANS APP