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Problem 30.10: Find resistance from power graph


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Assume an ideal battery. The graph shows the power dissipated by the variable resistor as a function of resistance (resistance is given in ohms and power is given in watts). Restart.

  1. For Circuit A, what is the value of the unknown resistor?
  2. What is the value of the power dissipated by the variable resistor when its resistance is equal to the unknown resistor?
  3. Move the slider to vary the resistance. When the variable resistor is equal to the unknown resistor, how does the power dissipated by the variable resistor compare to the power dissipated when the variable resistor is not equal to the unknown resistor?
  4. How can this help you find the unknown resistances in Circuit B and Circuit C?
  5. What are the unknown resistances in those circuits (to within about 10%)?

Problem authored by Anne J. Cox.

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