A circuit is
the route electricity follows from where it is generated to where
it is used.
Let's say that
you want to use the microwave oven. The electricity is routed through
your home's fuse box. You push the start button on the microwave and
you "close" a circuit loop for electrons to flow through. Electricity
now flows through a loop of wires from the electrical line outside
of your home to the microwave oven. When the food is cooked and you
turn the microwave off, the circuit is "opened". No electricity flows
to the microwave. That doesn't mean there isn't electricity in the
wires. If you cut into the cord with a pair of scissors, you would
be in for a deadly surprise. You would close the circuit, but now
the electrons would flow through you. Ouch.
| use circuits too. Sunlight hits a panel and triggers
the electrons to move through the cell. A wire leaves the cell,
continuing the circuit and after it passes through the appliance
(a lightbulb), the circuit moves back to the solar cell.
diagram shows the circuit between a battery and a lightbulb.
battery is the source of power. Electrons (electricity) flow
along the wire. The electricity goes through a lightswitch.
Inside the switch is a fuse that breaks the circuit. When
the switch is in the off position, the electricity cannot
travel through the wire. It is blocked. When the switch is
in the on position, the electricity can travel through the
restored circuit and make it to the lightbulb.