AP Physics 1 Question 20: Answer and Explanation

Test Information

Use your browser's back button to return to your test results.

Question: 20

10. An ideal battery of constant voltage V supplies current to a circuit that has total resistance R. If R is doubled, what will happen to the total power dissipated by the circuit?

  • A. It will double.
  • B. It will quadruple.
  • C. It will be halved.
  • D. It will remain the same.

Correct Answer: C


C Use the equation P = V2/R because we know V will remain constant despite this change (as opposed to current, which would be affected by the change). According to the equation, power dissipated is inversely proportional to resistance, so doubling resistance will cut the power dissipated in half.