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Need urgent help!! They say the ans is 41kW! But my ans comes 41MW! Please help!

A power transmission cable has a resistance of 12 ohms per meter, if it loses 500watts per km of length to heat, what is the output power if it delivers a p.d of 200000volts?
(edited 8 years ago)
Original post by Rubaiat
A power transmission cable has a resistance of 12 ohms per meter, if it loses 500watts per km of length to heat, what is the output power if it delivers a p.d of 200000volts?


Moved to physics. :smile:
Could you post your working out please?
Original post by rayquaza17
Moved to physics. :smile:
Could you post your working out please?


The correct answer is 41kW.

Please show how you arrived at your answer. The error is likely to be an incorrect exponent used during a multiplication or division.
Reply 3
Yeah I made a silly mistake! I multiplied 500W/km with 1000m! But i needed to divide it! As with decrease in distance...power dissipated will decrease!! 😊
Reply 4
Original post by Rubaiat
Yeah I made a silly mistake! I multiplied 500W/km with 1000m! But i needed to divide it! As with decrease in distance...power dissipated will decrease!! 😊


That was the problem...
Reply 5
Another question! What does "reflected and transmitted waves will always be in antiphase and therefore cancel out each other in a stationary wave" mean? If they cancel out eachother then how can a wave form? Is the statement true?

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