• They attract magnetic substances
• Like poles repel, unlike poles attract
• A freely suspended magnet points north-south direction
• Poles of magnet always exists in pairs.

The materials which are attracted by a magnet are called magnetic materials. The materials which are not attracted by a magnet are called non magnetic materials.

The magnetic field of a magnet is defined as the region around the magnet in which magnet or magnetic substance experiences a force The magnetic lines of force are the curves around the magnet along which a unit north pole would move if it was free to move.

They are:

• They move from N-pole to S-pole outside the magnet and from S-pole to N-pole internally.
• The magnetic lines of force do not intersect each other.

The neutral point is the point where the earth's magnetic field and the field due to the bar magnet becomes equal and opposite making the resultant field zero. At this point, magnetic compass does not show any fixed direction.

It is also considered that the earth is a huge magnet in which North pole lies at geographical south pole and south pole lies at the geographical north pole. When a bar magnet is freely suspended, north pole of a bar magnet is attracted by earth's magnetic south pole as opposite poles attract each other and turns towards north pole.

They are:

• Earth's crust contains magnetic substances, which may have produced earth's magnetism.
• The magnetic current circulating in its core due to convection currents, arising from radioactive heating inside the earth.

• A freely suspended magnet always points N-S direction.
• Neutral points are obtained on the magnetic field of a magnet which is due to combined effects of its magnetic field and earth's magnetic.

The angle madeby the intersection of the line joining the magnetic north-south (magnetic meridian) and the line joining the geographical north-south (geographical meridian) at a place is called angle of declination of that place. It is necessary while flying airplane during nights as well as sailingships in the ocean.

The angle made by the freely suspended magnet with the horizontal axis called the angle of dip or angle of inclination.
To measure the angle of dip, dip circle is used.

The figure shows the angle of dip at the poles. Its value is 900at this place because south pole of the dip needle becomes perpendicular to the geographical north pole and vice versa.

The value of angle of dip at the magnetic equator is 0⁰ and 90⁰ at the magnetic north pole.

The maximum value of angle of dip on the earth's surface is 90⁰ which is at the magnetic poles.

The angle of dip at Kathmandu is 42⁰ means that a dip needle will be inclined to horizontal axis by 42⁰ in Kathmandu.

The angle of declination in Kathmandu valley is 22⁰E means that N-pole of horizontal compass needle will point 22⁰ east to the geographical north and south direction.

Angle of declination	Angle of dip
It is the angle between magnetic meridian and geographical meridian at a place.	It is the angle made by a freely suspended magnet with the horizontal.
Its maximum value is less than 900.	Its maximum value is 900.

The component of earth's magnetic field along the horizontal direction is called the horizontal component of earth's magnetic field.