Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? They are not hard as copper brush They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes All of these They are not hard as copper brush They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor power output of 3-phase induction motor is 15 KW. The rotor copper losses at a slip of 4% will be 700 W 625 W 650 W 600 W 700 W 625 W 650 W 600 W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 1600 Volt. 2000 Volt. 1500 Volt. 0 Volt. 1600 Volt. 2000 Volt. 1500 Volt. 0 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic circuit of a dc shunt generator with negligible armature resistance and brush contact voltage drop remains unsaturated when it delivers full-load current at rated terminal voltage. The brushes are kept in the interpolar axis and speed is maintained constant. When the load is switched off, the terminal voltage would become zero decrease remain the same increase become zero decrease remain the same increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A small air gap in poly phase induction motor helps to reduce magnetizing current. increase starting torque. reduce chance of crawling. reduce chance of cogging. reduce magnetizing current. increase starting torque. reduce chance of crawling. reduce chance of cogging. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single-phase transformer has its maximum efficiency at 60 percent of full load. At full load copper loss will be less than core loss. more than core loss. zero. equal to core loss. less than core loss. more than core loss. zero. equal to core loss. ANSWER DOWNLOAD EXAMIANS APP