Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. 234.76 N-m. 266.20 N-m. can not be determined. 133.22 N-m 234.76 N-m. 266.20 N-m. can not be determined. 133.22 N-m ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the armature in the polar axis. commutator in the inter polar axis. commutator in the polar axis. armature midway between poles. armature in the polar axis. commutator in the inter polar axis. commutator in the polar axis. armature midway between poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field circuit of a DC shunt motor is opened The armature current will reduce. DC Shunt Motor The speed of motor will be reduced. The motor will attain dangerously high speed. The armature current will reduce. DC Shunt Motor The speed of motor will be reduced. The motor will attain dangerously high speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Exciting current of an induction motor is none of these. higher than power transformer. equal as power transformer. lesser than power transformer. none of these. higher than power transformer. equal as power transformer. lesser than power transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc motors, under leading pole tips flux density will--------? either increase or decrease increase None of these decrease either increase or decrease increase None of these decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP