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A distribution feeder of 1 km length having resistance, but negligible reactance, is fed from both the ends by 400 V, 50 Hz balanced sources. Both voltage sources S1 and S2 are in phase. The feeder supplies concentrated loads of unity power factor as shown in the figure. The contributions of S1 and S2 in 100 A current supplied at location P respectively, are

A distribution feeder of 1 km length having resistance, but negligible reactance, is fed from both the ends by 400 V, 50 Hz balanced sources. Both voltage sources S1 and S2 are in phase. The feeder supplies concentrated loads of unity power factor as shown in the figure. The contributions of S1 and S2 in 100 A current supplied at location P respectively, are Correct Answer 0 A and 100 A

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Let I be current supplied by source -1.

‘r’ be resistance / length

400 = (400 r) I + 200 r (I – 200) + (200 r) (I – 300) + (200 r) (I – 500) + 400

0 = 400r I + 200r I – 40000r + 200r I – 60000 + 200r I – 100000r 

⇒ I = 200 A

Current in branch – B is I – 200 = 200 – 200 = 0

For point P, source - 1 supplies OA current source 2 supplies 100 A current.

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