MAGNETS

A MAGNET is an object which can attract objects made of iron or mixtures of iron, such as steel. This attraction is called magnetism.

Magnets can be natural, such as the mineral magnetite, or artificial, such as magnets manufactured from metal.

Magnets have two poles: north and south. When the opposite poles of two magnets are placed together, the magnets attract each other. If the same poles are placed together, the magnets repel each other.

MAGNETIC FIELDS

Magnets create magnetic fields. They are the space around a magnet where materials, such as iron filings, are affected by magnetic forces.

ELECTROMAGNETS

An electromagnet is a conducting wire wrapped around a piece of iron, called a coil, which acts as a magnet when electrical current flows through it.

THE USES OF MAGNETS

Magnets are used in electric motors and generators for telephones, lights, televisions, computers and more.

- Magnetic recording media are used in audio cassettes, floppy disks and hard disk to store information in a very small space.

- Magnetic strips store information on credit cards.

- Electromagnets are used in televisions, computer monitors, loudspeakers and microphones.

ACTIVITY MAGNETS AND MAGNETISM

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1 An object which can attract other objects made of iron or mixtures of iron is called magnet
2 When the opposite poles of two magnets are placed together they atrack
3 When the same poles of two magnets are placed together they repel is other
4 The area around a magnet affected by magnetic forces is called a magnetic fields
5 A conducting wire wrapped around a piece of iron which acts as a magnet when an electrical current flows through the wire is called an electro magnet
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his fards in the beach

ELECTRICAL CURRENT

Electrical current is the flow of electrical charges. It transmits energy called electricity.

Electrical current flows differently, depending on the type of material through which it flows.

-Conductors:electrical current flows easily through conductors. Most metals are conductors.

-Insulators: electrical current does not flow easily through insulators, such as air, glass, plastic, wood and rubber.

ELECTRIC CIRCUITS

An electric circuit consist of different components connected to each other to allow the flow of an electrical current.

The four basic components of an electric circuit are:
- A generator, which is the source of electricity, such as an electrical plant or a battery.
-An electrical component, such as a light bulb or a motor.
- Conducting wires.
- A switch to control the flow of electrical current. a switch in the on position closes the circuit and allows the flow of electrical current. A switch in the off position opens the circuit and breaks the flow of electrical current.

ACTIVITY TRUE OR FALSE?

DECIDE IF THEY ARE TRUE OR FALSE, AND CORRECT THEM IF NECESSARY

1.Electrical current flows easily through conductors.
2.Rubber is a conductor.
3.Electrical current does not flow easily through insulators.
4.Most metals are insulators.
5.An electric circuit has four basic components.
6.When the switch is on, it opens the electric circuit.

ELECTRICAL CHARGES

There are two types of electrical charge: positive and negative. Negative charges can move from one place or object to another.

-If an object has more positive than negative charges, it is positively charged.
-If an object has more negative than positive charges, it is negatively charged.
-If an object has the same number of positive and negative charges, it is neutral.


Objects with opposite charges attract each other, and objects with the same charges repel each other.

If we rub an object with something made from a different material, we make electrical charges move, creating static electricity.


For example, if you rub a balloon onto your hair, negative charges move from tour hair onto the balloon. Your hair becomes positively charged and the balloon becomes negatively charged. You can stick the balloon to your hair, and your hair stands on end.

ACTIVITY ELECTRICITY AND MAGNETISM

COMPLETE THESE SENTENCES WITH THE CORRECT WORDS.

1. There are two types of electrical charges.
2. Negative charges can move from one place or object to another.
3. An object with the same number of positive and negative charges is neutral
4. Objects with opposite charges atract each other.
5. Objects with the same charges repel each other.