12. Magnetism

Magnetism Notes

Magnet : The body which attracts the iron substances it is called as magnet.

1) The earth natural magnet called as lodestone are magnetide

2. Magnet is found in the country magnesia.

3. There two poles of the magnet called as north pole and South pole.

Pole strength : The power of the pole to attract and substances it is called as pole strength.

1. For the north pole -- +m

2. For North pole -- -m

Magnetic Length : The distance from the north pole of the magnet to the South pole of the magnet it is called as magnetic length.

Geometric Length : The length which depends upon the shape and size of the magnet called as geometric length .

Axis of the Magnet : The line which passes to the both the poles of the magnet is called as axis of the magnet.

Equator of the Magnet : The line which passes through the centre of the magnet called as equator of the magnetic field.

Magnetic Field : The area surrounded by the magnet in which it can apply force called as magnetic field.

Magnetic lines of force : The lines of force starts from the north pole and ends on the South pole, by drawing a tangent give the direction of the magnetic field, it is called as magnetic lines of force.

Magnetic Induction : The magnetic lines of force per unit area is called as magnetic induction.

Unit : Tesla (T)

Magnetic Dipole Moment : The product of the pole strength and the finite length it is called as magnetic dipole moment.

M= m×2l

Properties of magnetic lines of force

1. Magnetic lines of force do not intersect each other.

2. The Magnetic lines of force starts from the north pole and ends on the South pole by, drawing a tangent it gives the direction of the magnetic field.

Earth Magnetism : The study of the earth magnetic field it is called as terrestrial magnetism. 

Geographic Axis : The straight line around which earth spin called as Geographic axis.

Geographic Meridian : At a given place, it is the vertical plane passing through the geographic North and South pole of the Earth 

Geographic Equator : It is a great circle on the surface of the earth. In a plane perpendicular to geographic axis.

Magnetic Axis : The straight line passing through the magnetic pole of the Earth. It is include to the Earth geography axis by nearly 11.3 degree.

Magnetic Meridian : At any place it is the vertical plane passing through the North and South pole of the Earth.

Magnetic Equator : It is a great circle on the surface of the Earth in a plane perpendicular to magnetic axis.

Magnetic Declination : The angle between the magnetic meridian and geographic Meridian at a place is called as magnetic declination.

Angle of dip : The angle between the Earth magnetic field at a place and the horizontal it is called as angle of dip.