Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.443. 0.512. 0.573. 0.649. 0.443. 0.512. 0.573. 0.649. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip test is performed to determine All of these direct axis reactance and quadrature axis reactance positive sequence reactance and negative sequence reactance slip All of these direct axis reactance and quadrature axis reactance positive sequence reactance and negative sequence reactance slip ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Inter pole winding is connected in-------------------------- ? series with main poles series with armature parallel with armature parallel with main poles series with main poles series with armature parallel with armature parallel with main poles ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An ideal synchronous motor has no starting torque because rotor is made up of salient poles. relative velocity between stator and rotor mmf’s is not zero. rotor winding is highly reactive. relative velocity between the stator and rotor mmf’s is zero. rotor is made up of salient poles. relative velocity between stator and rotor mmf’s is not zero. rotor winding is highly reactive. relative velocity between the stator and rotor mmf’s is zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In one 132 / 33 kV transformer the LV resistance is 0.02 per unit. The resistance referred to HV side is 0.08 pu. 0.02 pu. 0.16 pu. 0.01 pu. 0.08 pu. 0.02 pu. 0.16 pu. 0.01 pu. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 3 and 5 1 and 3 1, 2 and 3 1, 2, 3 and 5 1, 3 and 5 1 and 3 1, 2 and 3 1, 2, 3 and 5 ANSWER DOWNLOAD EXAMIANS APP