A 2-pole commutator machine,with 100 ampere turns, is runningat 1200 r.p.m. clockwise. The stationary flux of 0.12 Wb. perpole is sinusoidally is distributed in space. The brushes areseparated by an angle θ = 60 degree andthe centre line of brush separation coinsides with field axis.
(a) Find the magnitude of e.m.f. across the twobrushes.
(b) If the field flux of constant amplitude 0.12 Wb., isassumed to be rotating at 1800 r.p.m., in the (1) Clockwise direction and (2) anticlockwise direction, then compute the magnitude andefficiency of the brush e.m.f. when θ = 60 degree,Also calculate the frequency of conductor e.m.fs in both the cases.
(c) The armature at the other end of thecommutator is tapped and connected to balanced 3-Phase voltages, sothat a rotating field is produced, The speed of this rotating fieldis 3000 r.p.m. (1) clockwise and (2) anticlockwise,.Find thefrequency of the brush e.m.f. in the two cases.