MDCAT Physics MCQ #682

A circuit with two resistors in series and a voltage source has a total resistance of 15 ohms. If a third resistor is added in series, the new total resistance is 25 ohms. What is the resistance of the third resistor?

MDCAT Physics MCQ #682

  1. Question 1

    Q1. A circuit with two resistors in series and a voltage source has a total resistance of 15 ohms. If a third resistor is added in series, the new total resistance is 25 ohms. What is the resistance of the third resistor?

    • A) 5 ohms
    • B) 7.5 ohms
    • C) 10 ohms
    • D) 15/3 ohms

    Answer: 7.5 ohms

    Explanation: The resistance of the third resistor can be found by subtracting the initial total resistance from the new total resistance, resulting in a 10-ohm increase.