Power and electricity

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chocolatemonkey7
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#1
Report Thread starter 8 years ago
#1
http://www.ocr.org.uk/Images/58047-q...nd-photons.pdf

can you help me with question 2c
here is what i've done;
i) P=VI and so P=400000x440= 1.8x10^8
ii) 2000000000/1.8x10^8= 11.4 and so 12 cables.
iii) P=IV, P=I^2 x R
P= 440^2 x 0.052= 10kW
iv) i'm not really sure what to do. am i supposed to do 100 x 10kW x 12 (since there are 12 cables) and the what???
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chocolatemonkey7
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#2
Report Thread starter 8 years ago
#2
how much power lost would be 1.8 x 10^8-(100x10x1000).
and the would the (percentage loss be the power lost/ (1.8x10^8)) x 100 = 99.4 % ?
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chocolatemonkey7
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#3
Report Thread starter 8 years ago
#3
aha! so the percentage remaining would be ((power left (original power - power loss) / original power) x 100) which would be 99.4% thanks for clearing that up. .
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