Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 10% 5% 40% 19% 10% 5% 40% 19% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 31.1 Ω 15.1 Ω 15.9 Ω 31.9 Ω 31.1 Ω 15.1 Ω 15.9 Ω 31.9 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are identical as 4% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW? 200 MW and 400MW respectively generator 1 gets over load 230.7 MW and 369.23 MW respectively generator 2 gets over load 200 MW and 400MW respectively generator 1 gets over load 230.7 MW and 369.23 MW respectively generator 2 gets over load ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer maximum flux density is not constant, the eddy current loss varies as V² f² V f V² f² V f ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A part an alternator winding consist of eight coils in series, each having an emf of 20 V rms induced in it. Coils are placed in successive slots and between each slot and the next, there is an electrical phase displacement of 30°. Find the emf of eight coils in series 56.91 V. 66.91 V. 76.91 V. 86.91 V. 56.91 V. 66.91 V. 76.91 V. 86.91 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 8 Ω. 2 Ω. 10 Ω. 4 Ω. 8 Ω. 2 Ω. 10 Ω. 4 Ω. ANSWER DOWNLOAD EXAMIANS APP