First Children Encyclopedia

(Marvins-Underground-K-12) #1

237


Electricity


A battery.


Circuits of power


An electric circuit is a loop that electricity


can travel around. An electric current


moves through the wires in this circuit,


and lights up the bulb. Electrical cables


Electrical cables are made of
metal and plastic. Electricity
flows through the metal (which is
called a conductor). The plastic
(which is called an insulator)
stops electricity escaping.

High voltage


Electricity can be very


dangerous. This triangle


is an international


warning symbol. It


means “Caution: risk


of electric shock”.


Lightning strikes


When electricity builds


up in one place it is


called static electricity.


A bolt of lightning is


a huge spark of static


electricity in the sky.


Food battery
Food that contains water and weak
acid will conduct electricity. In a food
battery, a chemical reaction between
the metal and the acid in the food
creates an electric current.

Rub a party balloon up and
down on your clothes. The
balloon will now stick to the
wall. This is because rubbing
it gives the balloon an
electric charge.

Hands^ on


Circuits usually include an
energy source (battery)
and load (lamp).
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