Math Playground
Physics

Electricity-water analogy

Voltage as pressure, current as flow — make circuits intuitive.

Water analogy makes circuits intuitive.

Quick check

In the water analogy for circuits, what plays the role of a battery?

The full mapping

  • Voltage (V) — water pressure pushing the flow.
  • Current (A) — the flow rate, litres per second.
  • Resistance (Ω) — a narrow or kinked pipe restricting flow.
  • Battery — a pump adding pressure.
  • Capacitor — a stretchy membrane that stores a bit of pushed-back water.

The analogy makes Ohm's law obvious: more pressure (V) → more flow (I); a narrower pipe (higher R) → less flow. V = I·R.

Watch out

The analogy has limits. Water leaks out of a broken pipe; current doesn't 'leak out' of a broken wire — it simply stops, because the loop is open. Don't push the picture too far.

The mapping

  • Voltage — water pressure.
  • Current — flow rate.
  • Resistance — pipe narrowness.
  • Battery — pump.