Magnetism is a fundamental force of nature that manifests itself in various ways. It is the force that causes certain objects to attract or repel each other. Magnetism is closely related to electricity and is a result of the movement of charged particles, such as electrons.
Table of Contents
Here are some key points about magnetism:
1. Magnetic Field
A magnetic field is an area around a magnet or a current-carrying conductor where its influence can be felt. It is represented by lines of force that extend from the north pole of a magnet to its south pole. The strength and direction of the magnetic field are indicated by these lines.
2. Magnetic Poles
Magnets have two poles, commonly referred to as the north pole and the south pole. Like poles repel each other, while opposite poles attract. This behavior is known as the Law of Magnetic Poles.
3. Permanent Magnets
Some materials, such as iron, nickel, and cobalt, can be magnetized and retain their magnetism. These are called permanent magnets. They have their own magnetic fields and can exert forces on other magnets or magnetic materials.
An electromagnet is a magnet that is created by passing an electric current through a coil of wire. The magnetic field is produced by the movement of electrons in the wire. The strength of an electromagnet can be controlled by changing the amount of current flowing through the wire.
5. Magnetic Induction
Magnetic induction is the process by which a magnetic field is produced in a material when it is placed in a magnetic field. The material becomes temporarily magnetized while in the field and loses its magnetism when removed.
6. Applications of Magnetism
Magnetism has numerous practical applications in various fields. Some examples include electric motors, generators, transformers, magnetic storage devices (such as hard drives), magnetic resonance imaging (MRI) machines in medical diagnostics, magnetic levitation trains, and magnetic compasses.
7. Earth’s Magnetic Field
The Earth itself has its own magnetic field, generated by the movement of molten iron in its outer core. The Earth’s magnetic field is important for navigation, as it aligns with the planet’s rotational axis and can be used to determine direction using a magnetic compass.
Care or Maintenance of magnet
1. By using a keeper-A keeper is a piece of iron that is temporarily added between the north and south poles of a magnet to prevent demagnetization by redirecting the magnetic field.
2. Magnets should be stored in pairs.
3. Store in a dry place.
4. Store in a non –ferromagnetic container
5. Store in cool place
6. Magnets may be coated or case to prevent corrosion.
7. Magnet should not be heated as this will destroy the magnetic properties
USES OF MAGNETS
Magnets are useful in the following areas such as
-in appliances such as computer, electric generator, loudspeaker, microphone and electromagnets
1.Magnet is made from A. iron B. tin C. copper D. steel
2.Loadstone is naturally occurring magnet discovered in A. Britain B. America C. Germany D. China
3.Which of the following statements is correct? A. unlike poles repel B. like poles attract C. like poles repel D. unlike poles repel and attract
4.The following exert a field force except? A. magnet and pin B. electric force C. dragged table D. comb and hair.
5. A bar magnet has ________ poles A. one B. two C. three D. four
6. Magnet is used in all of the following except in A. cookers B. telegraph C generator D. loudspeakers.
7a. Explain how show magnetic force around a magnet
b. Demonstrate how to detect the North And South poles of a magnet
Understanding magnetism has played a significant role in technological advancements and has applications in numerous industries. It is a fascinating area of study that continues to uncover new discoveries and applications.