Series and Parallel Circuits

0:00Three identical bulbs can be wired to a battery in series or in parallel.

0:07Electrons flow only around a complete loop. Closing the switch completes it.

0:13The battery's push on the electrons is called voltage, measured in volts. One bulb alone gets all 6 volts.

0:23In series, we add bulbs one after another on the same single path.

0:29Now the three bulbs share the 6 volts, 2 volts each, so each one glows more dimly.

0:36Current is the charge passing a point each second, in amps. In series it is 0.2 amps everywhere.

0:45Many think the bulb nearest the battery lights first or glows brightest.

0:51In fact, all three light at once and glow equally: the current is the same all the way round.

0:58If one bulb breaks, the only path has a gap, so every bulb goes out.

1:04In parallel, each bulb sits on its own branch: a separate path back to the battery.

1:11Each branch gets the full 6 volts, so every bulb glows as brightly as one bulb alone.

1:17The branch currents add up: 0.6 plus 0.6 plus 0.6 makes 1.8 amps through the battery.

1:27If one bulb breaks, only its branch has a gap. The others are still complete, so they stay lit.

1:35That is why homes are wired in parallel: each light gets the full voltage and its own switch.

1:42In series, bulbs share one path. In parallel, each bulb has its own path and the full voltage.