All foundations
Unit 1 · What's going on? 6 minAge 8+

Resistance

Sometimes you want to slow electrons down. That's what resistance does.

Read first: Voltage and current

Imagine squeezing a garden hose while water is flowing. The tighter you squeeze, the less water comes out the other end — even though the pressure at the tap has not changed.

Electrons get squeezed too. A part called a resistor is the squeeze. The more resistance a circuit has, the less current can flow.

Drag the slider. Watch the LED dim and brighten.

You make the resistor bigger (more squeeze) but keep the battery the same. What happens?

Now you understand…

  • Resistance squeezes the electron flow.
  • Measured in ohms (Ω).
  • More resistance = less current, for the same voltage.

Electrons need somewhere to go. Time to close the loop.