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Two watt-meters connected to measure the total power on a three-phase system supplying a balanced load reads 10.5 kW and -2.5 kW respectively. Then the total power factor is?

Two watt-meters connected to measure the total power on a three-phase system supplying a balanced load reads 10.5 kW and -2.5 kW respectively. Then the total power factor is? Correct Answer 0.334

w1 = 10.5 kW, w2 = -2.5 kW ∴ w = w1 + w2 = 8 kW Also, tan ∅ = 2.81 ∴ ∅ = 70.43° or, cos ∅ = 0.3347.

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