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Homework Help: Generator from a power plant delivering electric power

  1. Nov 27, 2012 #1
    1. The problem statement, all variables and given/known data
    a generator of a large power plant delivers an electric power of 130mW at 22 kv AC. for transmission, this power is stepped up to 500kv by a transformer. what is the rms curret delivered by the generator? what is the rms current in the trnasmission line? by what factor the losses in the transmission line (on joule heating) are reduced by using a transformer? assume that the transformer is ideal and does not waste any power, and that transmission line is a purely resistive loads (no capacitance or inductance).

    2. Relevant equations
    Imax= ΔVrms/√(r^2+(xl-xc)^2)

    3. The attempt at a solution
  2. jcsd
  3. Nov 27, 2012 #2

    Andrew Mason

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    Homework Helper

    You just have to apply Ohm's law to determine the current. What is the current in the 22KVAC line. What is the current in the 500 KVAC line?

    What is the power loss in passing current I through a resistance R?

    From that you should be able to determine the relative line losses for the two currents (hint: put R at 1 ohm, say. Work out the power loss for each of the two lines and divide them).

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