Electrical Machines In a DC generator, if P be the number of poles and N be the rpm of the rotor, then frequency of magnetic reversals will be PN/60. PN/2. PN/3000. PN/120. PN/60. PN/2. PN/3000. PN/120. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature shaft must be able to withstand All of these bending moment due to weight of the armature. twisting strains due to transmission of torque. any unbalanced magnetic pull on the armature core. All of these bending moment due to weight of the armature. twisting strains due to transmission of torque. any unbalanced magnetic pull on the armature core. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In large sized DC machines the compensating windings are provided to neutralize voltage induced in coil due to fluctuation of l compensate for the decrease in speed due to increase of load. None of these reduce eddy current losses by providing local short circuits. neutralize voltage induced in coil due to fluctuation of l compensate for the decrease in speed due to increase of load. None of these reduce eddy current losses by providing local short circuits. ANSWER DOWNLOAD EXAMIANS APP
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. 1037.5 r.p.m. 963.8 r.p.m. 1130 r.p.m. 4575.4 r.p.m. 1037.5 r.p.m. 963.8 r.p.m. 1130 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Skewing of the rotor in a 3 - Φ squirrel cage induction motor reduces noise and parasitic torque, but increase starting and pull-out torque. noise and pullout torque, but increase parasitic and starting torque. noise, parasitic and starting torque, but increase pull out torque. noise, parasitic torque, starting torque and pull out torque. noise and parasitic torque, but increase starting and pull-out torque. noise and pullout torque, but increase parasitic and starting torque. noise, parasitic and starting torque, but increase pull out torque. noise, parasitic torque, starting torque and pull out torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation of the synchronous generator fails, it acts as a/an synchronous motor. induction motor. induction generator. synchronous generator. synchronous motor. induction motor. induction generator. synchronous generator. ANSWER DOWNLOAD EXAMIANS APP