Five Steps in Solving Ohm’s Law Problems

    1. Identify the Variables
    2. Write Down the Formula
    3. Substitute the Variables
    4. Solve
    5. Don’t Forget Units!

    Example Problem

    Determine the resistance of a lamp drawing 250 mA at 200 V.

    Example Solution

     I  = 250 mA = 0.25 A
    V  = 200 V
    R  = ?
    R  = V / I
     = 200 / 0.25
     = 800 Ω