Electrical Machines The material used for commutator brushes is mostly copper. mica. carbon. cast iron. copper. mica. carbon. cast iron. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 48.0%. 57.1%. 59.2%. 88.8%. 48.0%. 57.1%. 59.2%. 88.8%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following transformer insulating oil generally used in India? Paraffin based insulating oil. Aromatics based insulating oil. Naphtha based insulating oil. Olefin based insulating oil. Paraffin based insulating oil. Aromatics based insulating oil. Naphtha based insulating oil. Olefin based insulating oil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The maximum possible speed at which an alternator can be driven to generate 50 Hz and 4000 V is 3000 rpm. 3600 rpm. 4000 rpm. 1500 rpm. 3000 rpm. 3600 rpm. 4000 rpm. 1500 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A lap wound DC machine has 400 conductors and 8 poles. The voltage induced per conductor is 2 volts. The machine generates a voltage of 200 V. 800 V. 400 V. 100 V. 200 V. 800 V. 400 V. 100 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor has which of the following characteristics? Has its field winding consinting of thick wire and less no of turns. Has a almost constant speed. Has a poor torque. Can be started easily without load. Has its field winding consinting of thick wire and less no of turns. Has a almost constant speed. Has a poor torque. Can be started easily without load. ANSWER DOWNLOAD EXAMIANS APP