Physics

posted by .

Power transmission lines often use a form of electric current called alternating current, but in many regions, such as the Province of Quebec, high-voltage direct-current lines are used instead. Direct current is the kind of electric current you are studying in this chapter. A certain direct-current power transmission line has a resistance of 0.255 Ω/km. 812 kV of potential drives the current from the generating station to a city located 125 km from the plant. What is the power loss due to resistance in the line?

  • Physics -

    Rt = 0.255 Ohms/km * 125km = 31.875 Ohms. = Total rewsistance.

    Pl = I^2 * Rt = I^2 * 31.875 = Pwer lost.

    The power loss is proportional to the square of the current. Therefore, if we don't know how much current is flowing; we can't calculate the power loss.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. science

    why is current lower in a serie circuit than a parralel one?
  2. physics

    A large open loop made of metal is constructed below a high voltage (AC) power line. a) Can this loop be used to draw power from the lines?
  3. Science

    My question is, What was the function of a capacitor in an electric current?
  4. Physics

    1.How are alternating and direct current different?
  5. Physics

    A neighbourhood requires 1.5 x 10^5 w of electricity to power all homes during peak usage times. A step-down transformer is used on the high voltage transmission lines to lower the voltage to 120v for household use. There are 25000 …
  6. physics

    An electrical power plant generates electricity with a current of 50A and a potential difference of 20,000 V. In order to minimize the power losses due to the high current heating up the line, a transformer steps up the potential difference …
  7. science

    The potential difference measured across a coil is 20 V when a direct current of 2 A is passed through it. With an alternating current of 2 A at 40 Hz, the p.d. across the coil is 140 V. If the coil is connected to a 230 V, 50 Hz supply, …
  8. physcial science

    The type of current in your home is mostly A. direct current. B. alternating current. C. series current. D. produced by batteries.
  9. physcial science

    What type of current is produced by a battery?
  10. Physics/chemistry

    Which of the practices will lead to losses in electrical power transmission?

More Similar Questions