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This is a homework question I've been attempting. But the answer I get doesn't match with whats given and I don't understand why my method is wrong. This is the question with answers.

Question

Here's what I've done.

My Answer

I'm still new to these calculations. Thanks in advance.

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Basically you have (a) calculated the kVA loading correctly when the power factor is 0.65. In simple terms it's 55 kW ÷ 0.65 = 84.615 kVA.

You have also (b) calculated the current correctly i.e. 84.615 kVA ÷ 415 = 203.89 amps.

And, for (c) it looks like the set question is wrong because, when you have unity power factor, the power consumed by the load equals the VA hence, the answer is 55 kVA.

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    \$\begingroup\$ Since (a) and (c) are the same it appears that there’s a typo in the question. The question doesn’t state how the power factor is raised to unity, so the answer is undefined. \$\endgroup\$ – Frog Mar 9 at 10:40
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It looks like in the last question, you keep the current (203.89) and only change the power factor to 1. May be that is for showing that with same current and different power factor, KVA will not change.

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