A parallel circuit is way of connecting components on separate branches, so the current can take different routes around the circuit. The current is different in different parts of a parallel circuit.

The flashing is thanks to LEDs with a built-in, integrated flashing circuit and the nasty noise comes from a piezoelectric buzzer — both are available from electronics stores that sell ordinary LEDs.

We all carry supercomputers in our pockets and use dozens of electric gizmos every day but rarely stop to marvel at the magical act of flicking a switch. Use your ordinary conducting and extraordinary ...