Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Periodic variation of load. Over-loading for long period. Small and constant load. Over-excitation. Periodic variation of load. Over-loading for long period. Small and constant load. Over-excitation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. too rapid reversal of current. any of the above. over commutation. under commutation. too rapid reversal of current. any of the above. over commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The squirrel cage induction motors are provided with blades in order to balance the rotor dynamically. facilitate cooling of rotor. eliminate noise. none of these. balance the rotor dynamically. facilitate cooling of rotor. eliminate noise. none of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor electromotive force of the IM is observed to make 100 complete alterations per minute, calculated slip None of these 3 %. 3.33 %. 0 .001 %. None of these 3 %. 3.33 %. 0 .001 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 100/10, 50 VA double winding transformer is converted to 100/110 V auto transformer. The rating of auto transformer is 550 VA 100 VA 110 VA 500 VA 550 VA 100 VA 110 VA 500 VA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The result of slip test on a 3-phase, 20 KVA, 400 V, 50 Hz connected salient pole alternator is given below- Phase value: Vmax = 100 V, Vmin = 96 V, Imax = 10 A and I min = 7 A. The direct and quadranature axis reactances are respectively 8.248 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 5.54 Ω. 14.28 and 9.60 Ω. 8.248 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 5.54 Ω. 14.28 and 9.60 Ω. ANSWER DOWNLOAD EXAMIANS APP