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 36 W. 28 W. 25 W. 30 W. 36 W. 28 W. 25 W. 30 W. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 1, 2, 5 2, 3, 6 2, 4, 5, 6 3, 4, 5 1, 2, 5 2, 3, 6 2, 4, 5, 6 3, 4, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor has which of the following characteristics? Has a almost constant speed. Has its field winding consinting of thick wire and less no of turns. Can be started easily without load. Has a poor torque. Has a almost constant speed. Has its field winding consinting of thick wire and less no of turns. Can be started easily without load. Has a poor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer cooling and insulating oil must be of low resistivity. high viscosity. low viscosity. low BDV. low resistivity. high viscosity. low viscosity. low BDV. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A compound dc generator is delivering full load current at a terminal voltage of 230 V. Its series-field winding gets short circuited. If its terminal voltage 1. becomes more than 230 V, it is overcompounded generator 2. becomes more than 230 V, it is differentially compounded generator 3. becomes less than 230 V, it is overcompounded generator 4. becomes less than 230 V, it is differentially compounded generator 5. becomes less than 230 V, it is level compounded generator From these, the correct answer is 1, 4 2, 3, 5 2,3 1, 4, 5 1, 4 2, 3, 5 2,3 1, 4, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 100 KVA transformer is operating at 60 Hz, 240 V supply. The same transformer is operating at 50 Hz, 200 V supply. The new rating is 123.3 KVA 83.33 KVA 50 KVA 100 KVA 123.3 KVA 83.33 KVA 50 KVA 100 KVA ANSWER DOWNLOAD EXAMIANS APP