Electrical Machines Which of the following represents the pitch factor? Cos α Cos α² Cos (α/2) sin (α/2) Cos α Cos α² Cos (α/2) sin (α/2) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the phase difference between two windings of A.C servomotor ? 120°. 60°. 30°. 90°. 120°. 60°. 30°. 90°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 2, 4 ,5 2, 3 , 5 1, 3, 5 1, 4 2, 4 ,5 2, 3 , 5 1, 3, 5 1, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by increasing field excitation. fixing the brush axis inline with the pole axis. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. increasing field excitation. fixing the brush axis inline with the pole axis. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. 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? 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. 1130 r.p.m. 1037.5 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines On which of the following factor/factors the speed of a DC motor depends upon? Armature current. Field flux. All of these. Applied voltage. Armature current. Field flux. All of these. Applied voltage. ANSWER DOWNLOAD EXAMIANS APP