Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is (3/2)Fmax. 3Fmax. Fmax. (1/2)Fmax. (3/2)Fmax. 3Fmax. Fmax. (1/2)Fmax. 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 14.28 and 5.54 Ω. 14.28 and 9.60 Ω. 8.248 and 9.60 Ω. 8.248 and 5.54 Ω. 14.28 and 5.54 Ω. 14.28 and 9.60 Ω. 8.248 and 9.60 Ω. 8.248 and 5.54 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward Leonard control is provides speed control Above rated speed. In one direction only. In both direction. Below rated speed. Above rated speed. In one direction only. In both direction. Below rated speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a practical synchronous motor the pull out torque will occur when the torque angle is nearly equal to 30°. 75°. 0°. 45°. 30°. 75°. 0°. 45°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a step down transformer which one of the following statements is true? Secondary power is less than primary power. Secondary current is less than primary current. Number of secondary turns is less than primary turns. Number of secondary turns is more than that of primary. Secondary power is less than primary power. Secondary current is less than primary current. Number of secondary turns is less than primary turns. Number of secondary turns is more than that of primary. 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? 1130 r.p.m. 1037.5 r.p.m. 963.8 r.p.m. 4575.4 r.p.m. 1130 r.p.m. 1037.5 r.p.m. 963.8 r.p.m. 4575.4 r.p.m. ANSWER DOWNLOAD EXAMIANS APP