Electrical Machines The maximum possible speed at which an alternator can be driven to generate 50 Hz and 4000 V is 4000 rpm. 1500 rpm. 3000 rpm. 3600 rpm. 4000 rpm. 1500 rpm. 3000 rpm. 3600 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has hysteresis loss of 30 W, at 240 V, 60 Hz. The hysteresis loss at 200 V, 50 Hz will be 30 W. 36 W. 28 W. 25 W. 30 W. 36 W. 28 W. 25 W. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole DC generator rotates at 1500 rpm. How many times in a second, will the emf induced in each armature conductor changes its direction? 750. 500. 200. 100. 750. 500. 200. 100. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms connected directly to a 220 Volt supply. If the armature is stationary then the current flowing through the armature is 250 A. 440 A. 570 A. 340 A. 250 A. 440 A. 570 A. 340 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if the field flux axis is ahead of the armature field axis in the direction of rotation, the machine operating is synchronous motor. asynchronous motor. synchronous generator. asynchronous generator. synchronous motor. asynchronous motor. synchronous generator. asynchronous generator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the field winding connection must be reversed the field winding must be replaced the armature connection must be reversed field winding must be excited by low voltage dc supply the field winding connection must be reversed the field winding must be replaced the armature connection must be reversed field winding must be excited by low voltage dc supply ANSWER DOWNLOAD EXAMIANS APP