Variant 7

Current Electricity – is caused by tiny invisible things called electrons that move through metal. This flow is called an electric current. Objects that need current electricity (moving electricity) are powered by batteries or by electricity which travels along wires from a power station. The circuit is completed by a switch, which turns the appliance on. When the switch is turned off, the circuit is broken and the appliance is turned off.

Many objects that we use in our every day routine are powered by electricity – from computers and hairdryers to lamps and washing machines.

Electricity can be very dangerous.  You should never touch anything electrical with wet hands – and that includes any electrical switches. Electricity can be conducted through sweat (salty water) to your body, giving you an electric shock - so think before you touch.

Variant 8

Conductors allow electricity flow through them.  Conductors are materials that can carry electricity - they conduct electricity. Metal materials such as copper, iron, steel and aluminum are all good conductors of electricity.

Insulators do not allow electricity to flow through them. Materials such as wood, plastic, rubber and glass do not carry electricity and are called insulators – they don’t conduct electricity.

Insulators and conductors both have important uses in current electricity. Electricity can be very dangerous.  You should never touch anything electrical with wet hands – and that includes any electrical switches. Electricity can be conducted through sweat (salty water) to your body, giving you an electric shock - so think before you touch.

Variant 9

Magnets have a special power that enables them to attract other magnetic things such as iron, steel, cobalt and nickel. Magnets have two main forces - push and pull. As you will see from these magnetic experiments, magnetism (the invisible force) can push and pull through some materials such as paper and plastic.

Paper clips are made of steel.  If you hold a paper clip close to a magnet, you can feel the magnet pulling on the paper clip with an invisible force called magnetism.

All magnets have two ends or poles (North & South).  If you put the poles of two magnets together, they will either pull together or push apart.  They will pull (attract) each other if the poles are different.  They will push (repel) each other if the poles are the same.

Experiments with magnets will help you to find out more about the way magnetism works and how it can be passed on to some other objects.

Variant 10

Direct current (DC) is the continuous flow of electricity through a conductor such as a wire from high to low potential. In direct current, the electric charges flow always in the same direction, which distinguishes it from alternating current (AC).

Direct current was used originally for electric power transmission after the discovery by Thomas Edison of the generation of electricity in the late nineteenth century. It has mostly been abandoned for this purpose in favor of alternating current which is much more suited to transmission over long distances. DC power transmission is still used to link AC power networks with different frequencies

An alternating current is an electric current that changes direction at regular intervals. When a conductor is moved back and forth in a magnetic field, the flow of current in the conductor will reverse direction as often as the physical motion of the conductor reverses direction.