Which equation expresses Ohm's Law relating voltage, current, and resistance?

Which equation expresses Ohm's Law relating voltage, current, and resistance?

• A. V = I R
• B. P = V I
• C. I = V R
• D. R = V / I^2

Answer: (A)

Voltage, current, and resistance relate through Ohm's Law in the form V = IR. This shows that the voltage across a conductor equals the current flowing through it multiplied by its resistance. The units line up: amperes times ohms give volts. This form also makes it easy to solve for any one quantity if the other two are known (I = V/R and R = V/I are valid rearrangements). The other options don’t express the direct three-way relationship: one is a power formula (P = VI), and the others misstate the relationship by using multiplication where division is required.

Voltage, current, and resistance relate through Ohm's Law in the form V = IR. This shows that the voltage across a conductor equals the current flowing through it multiplied by its resistance. The units line up: amperes times ohms give volts. This form also makes it easy to solve for any one quantity if the other two are known (I = V/R and R = V/I are valid rearrangements). The other options don’t express the direct three-way relationship: one is a power formula (P = VI), and the others misstate the relationship by using multiplication where division is required.