Which equation expresses Ohm's Law?

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Multiple Choice

Which equation expresses Ohm's Law?

Ohm’s Law describes how voltage, current, and resistance relate to each other, with voltage being the product of current and resistance. This direct relationship is captured by V = IR, so the expression that matches this fundamental connection is the correct one. It shows how increasing current or resistance changes the voltage across a conductor. The other forms don’t fit the basic relationship. I = V + R would add voltage and resistance, which doesn’t describe how current behaves. R = V - I would subtract current from voltage, which also doesn’t align with the units or the physics. P = VI represents electrical power, not the basic voltage–current–resistance link (though power can be derived from Ohm’s Law as P = I^2R or P = V^2/R). You can, of course, rearrange V = IR to I = V/R or R = V/I if you need a different variable, but the direct Ohm’s Law expression is V = IR.

Ohm’s Law describes how voltage, current, and resistance relate to each other, with voltage being the product of current and resistance. This direct relationship is captured by V = IR, so the expression that matches this fundamental connection is the correct one. It shows how increasing current or resistance changes the voltage across a conductor.

The other forms don’t fit the basic relationship. I = V + R would add voltage and resistance, which doesn’t describe how current behaves. R = V - I would subtract current from voltage, which also doesn’t align with the units or the physics. P = VI represents electrical power, not the basic voltage–current–resistance link (though power can be derived from Ohm’s Law as P = I^2R or P = V^2/R). You can, of course, rearrange V = IR to I = V/R or R = V/I if you need a different variable, but the direct Ohm’s Law expression is V = IR.

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