Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2 A armature current at no-load, when the armature current is changed to 20 A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 1130 r.p.m. 4575.4 r.p.m. 1037.5 r.p.m. none of above. 1130 r.p.m. 4575.4 r.p.m. 1037.5 r.p.m. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two DC series motors are connected in series and are driving the same mechanical load. If the motors are now connected in parallel the speed will become one fourth. 4 times. half. double. one fourth. 4 times. half. double. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Iron loss in a transformer mainly occurs in winding of transformer. steel core in transformer. transformer insulating oil. iron made tank of transformer. winding of transformer. steel core in transformer. transformer insulating oil. iron made tank of transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will increase to 1.25 times 220 V increase to a value greater than 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V not change and remain at 220 V increase to 1.25 times 220 V increase to a value greater than 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V not change and remain at 220 V 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 2, 3, 6 1, 2, 5 3, 4, 5 2, 4, 5, 6 2, 3, 6 1, 2, 5 3, 4, 5 2, 4, 5, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For very sensitive and wide speed control, the preferable control method is Multiple voltage control. Field control. Armature control. Ward-Leonard control. Multiple voltage control. Field control. Armature control. Ward-Leonard control. ANSWER DOWNLOAD EXAMIANS APP
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