Ohm’s Law defines the relationship between the three most basic electrical quantities. It states that the current flowing through a conductor is directly proportional to the voltage across it and inversely proportional to the resistance.

Audio Explanation

Prefer to listen? Here's a breakdown of how pressure, flow, and friction work together in a circuit.

Visual Representation

The Water Analogy Voltage (Pressure) Resistance (Narrow Pipe) Current (Flow Rate)

The Big Three Variables

  • Voltage ($V$): The electrical “pressure” or potential difference. Measured in Volts (V).
  • Current ($I$): The rate at which charge flows. Measured in Amperes (A).
  • Resistance ($R$): The opposition to the flow of charge. Measured in Ohms ($\Omega$).

The Formula

\(V = I \times R\)

Interactive Ohm’s Law Lab

Adjust the sliders for Voltage and Resistance. Watch how the size of the “I” (Current) changes in real-time. If you double the voltage while keeping resistance the same, the current will double!

V = IR Explorer

6 V
500 Ω

Current (I):

0.012 A

Interactive Match: Ohm’s Law

💡 Quick Concept Check:

If a lightbulb has a resistance of 240 Ω and is plugged into a 120 V outlet, how much current flows through it?

Click to Reveal Answer
Using $I = V / R$: $I = 120\text{ V} / 240\text{ }\Omega = \mathbf{0.5\text{ A}}$.
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