Electrical Machines A shunt generator has a critical field resistance of 300 Ω at a speed of 800 rpm if the speed is raised to 1000 rpm the critical field resistance is 375 Ω. 145 Ω. 225 Ω. 150 Ω. 375 Ω. 145 Ω. 225 Ω. 150 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Inter pole winding is connected in-------------------------- ? series with armature parallel with main poles parallel with armature series with main poles series with armature parallel with main poles parallel with armature series with main poles ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then I1 > I2 None of these I1 < I2 I1 = I2 I1 > I2 None of these I1 < I2 I1 = I2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC machine having P no of pole pairs Z no of conductors having length L of resistivity ρ and cross section S are arranged. what is the armature resistance for lap-winding ? PZL/4SP² PZL/4Sa² PZL/ 4Sa PZL/4S PZL/4SP² PZL/4Sa² PZL/ 4Sa PZL/4S ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following DC motors has almost constant speed over their full load range? none of these. Series. Shunt. Compound (cummolative). none of these. Series. Shunt. Compound (cummolative). ANSWER DOWNLOAD EXAMIANS APP