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Homework Help: Electricity question on the power generated by power stations.

  1. Apr 14, 2013 #1
    1. The problem statement, all variables and given/known data

    2)The power stations providing electricity for the National Grid generate electricity at 25kV. The typical demand on an average winter's day in the north-west of England is 6000MW. The current output form the generators is 240kV. Transformers raise the transmission voltage to 400kV. Assuming 100% efficiency in the transformers, the current is 15kA. Each pair of 400kV supergrid conductors has a resistance of 0.034Ωk/m.
    How much power is lost per kilometre heating the conductors?
    Books answer:7.65MW

    2. Relevant equations


    3. The attempt at a solution
    Can type my working out sorry.
  2. jcsd
  3. Apr 14, 2013 #2


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    Staff: Mentor

    We don't know how to help if you don't show your attempt...
  4. Apr 14, 2013 #3
    We can't help you unless we can see you have tried to solve it.
  5. Apr 14, 2013 #4
    Are you sure you copied that text correctly? It seems to contain several errors. For example it should be 0.034Ω/km, not 0.034Ωk/m.
    So each km of conductor has a resistance of 0.034Ω. The current is 15kA.
    Now you just have to apply your equations.
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