What is the Ohm's Law equation?

What is the Ohm's Law equation?

• A. I = VR
• B. P = VI
• C. V = IR
• D. E = IR

Answer: (C)

Ohm's Law shows how voltage, current, and resistance relate in a circuit element. The standard form is V = IR, meaning voltage equals current times resistance. This tells you that for a given resistance, increasing the voltage raises the current proportionally, with the resistance being the proportionality constant. For example, a 3-ohm resistor with 6 volts across it has a current of 6/3 = 2 amperes, and the voltage across it is 2 A × 3 Ω = 6 V. The other expressions mix the roles or describe different quantities (I = VR would give incorrect units for current; P = VI is power, not the basic voltage–current–resistance link; E = IR isn’t the standard form for a simple resistor). The direct, commonly used equation to memorize is V = IR.

Ohm's Law shows how voltage, current, and resistance relate in a circuit element. The standard form is V = IR, meaning voltage equals current times resistance. This tells you that for a given resistance, increasing the voltage raises the current proportionally, with the resistance being the proportionality constant. For example, a 3-ohm resistor with 6 volts across it has a current of 6/3 = 2 amperes, and the voltage across it is 2 A × 3 Ω = 6 V. The other expressions mix the roles or describe different quantities (I = VR would give incorrect units for current; P = VI is power, not the basic voltage–current–resistance link; E = IR isn’t the standard form for a simple resistor). The direct, commonly used equation to memorize is V = IR.