Electrical Machines A 3 - Φ, 4 pole IM is supplied from a 50 Hz source. Calculate rotor frequency when rotor runs 600 rpm? 30 Hz. 35 Hz. Can be determined. 20 Hz. 30 Hz. 35 Hz. Can be determined. 20 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 50 Hz. 16.67 Hz. 25 Hz. 60 Hz. 50 Hz. 16.67 Hz. 25 Hz. 60 Hz. ANSWER DOWNLOAD EXAMIANS APP
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? none of above. 1130 r.p.m. 1037.5 r.p.m. 4575.4 r.p.m. none of above. 1130 r.p.m. 1037.5 r.p.m. 4575.4 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 3 3 only 1, 2, 3 and 4 1, 2 and 3 1, 3 3 only 1, 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which slots are used in the rotor of an induction motor? None of above. Open slots. Closed slots. Semi closed slots. None of above. Open slots. Closed slots. Semi closed slots. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 1 at 90°C. 0.5 at 90°C. 3 at 90°C. 2 at 90°C. 1 at 90°C. 0.5 at 90°C. 3 at 90°C. 2 at 90°C. ANSWER DOWNLOAD EXAMIANS APP