Electrical Machines The rotor speed of an induction motor is given by None of these Ns = 120f /p × ( 1 - r). Nr = 120f / p × (1-s). Ns = 120f / p × ( 1 - s ). None of these Ns = 120f /p × ( 1 - r). Nr = 120f / p × (1-s). Ns = 120f / p × ( 1 - s ). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Rf maximum and Ra minimum Ra maximum and Rf minimum Ra minimum and Rf minimum Ra maximum and Rf maximum Rf maximum and Ra minimum Ra maximum and Rf minimum Ra minimum and Rf minimum Ra maximum and Rf maximum ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase slip-ring induction motor, brushes are connected to DC supply. 3 - Φ AC supply. equalizing coils. external star-connected resistors. DC supply. 3 - Φ AC supply. equalizing coils. external star-connected resistors. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Induction motors normally use cast aluminium rotor because aluminium is cheaper in cost. easy to cast owing to its low melting point and is easily available. lighter in weight. of low resistivity. cheaper in cost. easy to cast owing to its low melting point and is easily available. lighter in weight. of low resistivity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators mainly to reduce the eddy currents by providing local short circuit. to provide path for the circulation of cooling air. None of these to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. to provide path for the circulation of cooling air. None of these to neutralize the cross magnetizing effect of the armature reaction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 80. 50. 18. 36. 80. 50. 18. 36. ANSWER DOWNLOAD EXAMIANS APP
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