Energy efficiency, Transformer?

AI Thread Summary
The discussion focuses on calculating the current flowing through long-distance power transmission wires after voltage transformation. The power plant generates electricity at 12693 V, which is stepped up to 528900 V using a transformer with specific turns in the coils. The efficiency of the wires is noted as 99.30%, and their resistance is 1089 Ω. The initial calculations attempted to use Ohm's Law (V=IR) but failed to account for voltage drop due to resistance along the transmission line. Clarification is provided that the voltage received at the far end will differ from the sending voltage due to this drop, emphasizing the importance of considering efficiency and resistance in current calculations.
Daisy
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Homework Statement



A power plant produces energy at a voltage of Vi = 12693 V. Before being sent along long distance power lines this electricity is sent through a transformer with 166 turns in the primary coil and 6917 turns in the secondary coil. The voltage of the electricity sent through the long distance wires is 528900V.
If the wires have an efficiency of 99.30% and a resistance of 1089 Ω, what current flows through these wires?

Homework Equations



I have used V=IR. Of which I got V to be 485.67 and I mil

The Attempt at a Solution


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I got I = V/R to be 485.67 and I multiplied it by 0.993 in order to determine the current flowing through these wires. But I got it wrong. I don't seem to understand what is wrong. Did I use the correct equation? Or was my computation of efficiency incorrect?
 
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R is the resistance of the transmission wires and doesn't include any load resistance at the receiving end. That means your current calculation is not correct.

Instead, start by writing an expression for the voltage received at the far end assuming some (as yet unknown) current ##I## is flowing.

Next consider the definition of Efficiency in this context (power transmission).
 
I am really confused. What do you mean by voltage received at the far end?
 
Daisy said:
I am really confused. What do you mean by voltage received at the far end?
Power station at one end of the transmission line, some load at the far end. The transmission line has resistance so there will be a voltage drop between the sending end and the receiving end. Thus the voltage received at the far end is not the same as the voltage at the sending end.
 
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