In an electric circuit with a resistor, Ohm's law is:

In an electric circuit with a resistor, Ohm's law is:

• A. P = VI
• B. I = V/R
• C. R = V/I
• D. V = IR

Answer: (D)

Ohm's law in a resistor shows how voltage, current, and resistance relate: the voltage across the resistor equals the current through it times its resistance. This direct form is V = IR. It tells you, for a given resistance, how the voltage and current scale together: doubling the current doubles the voltage if resistance stays the same. The other expressions simply rearrange that same relationship: I = V/R and R = V/I are equivalent ways to describe the same link between the three quantities. P = VI, on the other hand, is the power formula and describes how much electrical power is being dissipated, not the basic voltage–current–resistance relationship.

Ohm's law in a resistor shows how voltage, current, and resistance relate: the voltage across the resistor equals the current through it times its resistance. This direct form is V = IR. It tells you, for a given resistance, how the voltage and current scale together: doubling the current doubles the voltage if resistance stays the same.

The other expressions simply rearrange that same relationship: I = V/R and R = V/I are equivalent ways to describe the same link between the three quantities. P = VI, on the other hand, is the power formula and describes how much electrical power is being dissipated, not the basic voltage–current–resistance relationship.