V = IR is an expression of

• A. Power Law
• B. Kirchhoff's Law
• C. Watt's Law
• D. Ohm's Law

Answer: (D)

Ohm's Law describes how voltage, current, and resistance relate in a circuit. For a component with constant resistance, the voltage across it equals the current through it times its resistance: V = I × R. This means voltage rises proportionally with current when resistance is fixed, and it also lets you solve for any one quantity if you know the other two (I = V/R and R = V/I). The units align cleanly: a volt is the product of an ampere and an ohm.

It’s different from a power relation, since power in a circuit is P = VI (or P = I^2R or P = V^2/R). It’s not describing conservation around a loop or a node, which is what Kirchhoff’s laws cover. And there isn’t a standard fundamental “Watt’s Law” that mirrors V = IR.