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Jake asked in Science & MathematicsPhysics · 2 months ago

Two resistors A and B are connected in parallel across a 12V battery. The current through B is found to be 1.6A. When the two resistors are?

connected in series to the 12 V battery,

a voltmeter connected across resistor A measures a voltage of 6.7V.

Find the resistance of B.

Answer in units of Ω.

Find the resistance of A.

Answer in units of Ω.

1 Answer

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  • NCS
    Lv 7
    2 months ago
    Favorite Answer

    Welcome to Yahoo!Answers.

    When in parallel, the voltage drop across both resistors must be the same, so for B,

    R = V / I = 12V / 1.6A = 7.5 Ω ◄ resistance B

    When in series, if the drop across A is 6.7 V, then the drop across B must be 5.3 V. Find the current:

    I = V / R = 5.3V / 7.5Ω = 0.71 A

    That must also be the current in A, so

    R = 6.7V / 0.71A = 9.5 Ω ◄ resistance A

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