Which expression represents the formula to solve for resistance in Ohm's law?

Which expression represents the formula to solve for resistance in Ohm's law?

• A. R = I / E
• B. R = E * I
• C. R = E / I
• D. R = V / I

Answer: (C)

To solve for resistance, start from Ohm’s law: voltage equals current times resistance, V = I R. Isolate R by dividing both sides by I, giving R = V / I. In this question, the symbol used for voltage is E, so the corresponding form is R = E / I. This matches the given expression because it uses the same voltage symbol used in the problem. The other forms either place the terms in a way that changes the relationship (R = I / E would be the reciprocal, not resistance) or multiply voltage by current (E × I) which isn’t resistance, and the form with V / I would be correct only if the voltage were labeled V.

To solve for resistance, start from Ohm’s law: voltage equals current times resistance, V = I R. Isolate R by dividing both sides by I, giving R = V / I. In this question, the symbol used for voltage is E, so the corresponding form is R = E / I. This matches the given expression because it uses the same voltage symbol used in the problem. The other forms either place the terms in a way that changes the relationship (R = I / E would be the reciprocal, not resistance) or multiply voltage by current (E × I) which isn’t resistance, and the form with V / I would be correct only if the voltage were labeled V.