# Magnetism: Magnets and Magnetic Fields

## Magnetism: Magnets and Magnetic Fields

• A magnet is an object that produces a magnetic field. It has the ability to attract ferromagnetic materials such as iron, nickel, and cobalt.

• There are two types of magnets: permanent magnets and temporary magnets. Permanent magnets keep their magnetic properties for a long time while temporary magnets lose their magnetism when not in a magnetic field.

• All magnets have two poles: north and south. As per the rule, like poles repel each other while opposite poles attract each other.

• The space around a magnet, where the force of magnetism acts, is called a magnetic field. They are represented by the field lines, which go from the north pole to the south pole.

• The region of strongest magnetic force is at the ends of the magnet, usually referred as poles.

• Magnetic fields can be visualised or detected using plotting compasses and iron filings.

• The Earth itself acts like a giant magnet with a magnetic field, called the geomagnetic field. The pole near geographic north is actually the magnetic south pole and vice versa.

• The motion of charged particles can be influenced by a magnetic field. This principle is applied in devices such as electric motors and generators.

• Electromagnets are created by running a current through a coil of wire. The strength of an electromagnet can be increased by adding more coils, increasing the current, or inserting a magnetic material such as iron in the coil.

• In electromagnetic induction, a changing magnetic field creates an electric current. This phenomenon has vast applications in the generation of electricity.

• The left-hand rule, or Fleming’s Left Hand Rule, is used to find the direction of motion in an electric motor. The thumb represents the direction of force or motion, the index finger represents the magnetic field (from North to South) and the middle finger represents the current (from positive to negative).

• Similarly, the right-hand rule, or Fleming’s Right Hand Rule, is used to determine the direction of induced current in a conductor moving in a magnetic field. The thumb represents motion, the index finger the field, and the middle finger the current.