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A 440 V, 4-pole, 25 kW, dc generator has a wave-connected armature winding with 846 conductors. The mean flux density in the air-gap under the interpoles is 0.5 Wb/m2 on full load and the radial gap length is 0.3 cm. Number of turns required on each interpole is _________

A 440 V, 4-pole, 25 kW, dc generator has a wave-connected armature winding with 846 conductors. The mean flux density in the air-gap under the interpoles is 0.5 Wb/m2 on full load and the radial gap length is 0.3 cm. Number of turns required on each interpole is _________ Correct Answer 74

Corresponding value of ampere-turns for an interpole ATi = ATa (peak) +(Bi/µ0) lgi. = Ia* Z/2*A*P + (Bi/µ0) lgi. Assuming Ia = Iline Ia = 25*103/440= 56.82 A. ATi = +(0.5/4π*10-7 )* 0.3*10-2 =4198. Ni= 4198/56.82= 74.

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