Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 4575.4 r.p.m. 963.8 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 4575.4 r.p.m. 963.8 r.p.m. 1037.5 r.p.m. 1130 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The condition for maximum running torque is unity 0.5 lagging 0.707 lagging zero R = S.X unity 0.5 lagging 0.707 lagging zero R = S.X ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Motor is driving a constant load torque having armature resistance of 0.25 Ω and armature current of 60 A having connected to a voltage of 230 V. Now a resistance of 1 ohm is added into the armature circuit. The ratio of their speed will be 0.25. 0.72. 1.24. 0.62. 0.25. 0.72. 1.24. 0.62. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then E ∝ φ/f E ∝ 1/(φf) E ∝ φf E ∝ f/φ E ∝ φ/f E ∝ 1/(φf) E ∝ φf E ∝ f/φ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Fifth harmonic component of the induced voltage in three phase AC generator can be eliminated by using a winding pitch of 2 / 3. 5 / 6. 6 / 7. 4 / 5. 2 / 3. 5 / 6. 6 / 7. 4 / 5. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine the armature mmf is stationary with respect to armature. rotating with respect to field poles as well as armature. stationary with respect to field poles. rotating with respect to field poles. stationary with respect to armature. rotating with respect to field poles as well as armature. stationary with respect to field poles. rotating with respect to field poles. ANSWER DOWNLOAD EXAMIANS APP