Magnetism and Electromagnetism

Electric field and magnetic field are not independent. They are two aspects of the electromagnetic field. Charge at rest only produces electric field. Moving charge produces both electric field and magnetic field.

Magnetic lines of force are always closed loops, unlike electric lines of force which start from positive charges and end on negative charges (or infinity). Therefore, magnetic lines are not open.

Electric field lines are discontinuous because they terminate on charges. Magnetic field lines are continuous because they form closed loops and have no magnetic monopoles. The reason correctly explains the behavior inside conductors and magnets.

A magnetic domain is a region within a magnetic material in which the magnetization is in a uniform direction. This means that the individual magnetic moments of the atoms are aligned with one another and they point in the same direction.

An electron is not a spinning ball of charge and the intrinsic spin of particles cannot be understood in such terms. a value of the ratio between the magnetic moment and the angular momentum that is a factor 2 too small.

A magnetic domain is the region in which the magnetic fields of atoms are grouped together and aligned. In an unmagnetized object the magnetic domains are pointing at different directions.

Atomic currents and intrinsic spins of electrons are responsible for origin of magnetism.

Electric generator was faradays law of electromagnetic induction,a changing magnetic flux gives rise to electric current.

Magnetization. There are a variety of methods that can be used to establish a magnetic field in a component for evaluation using magnetic particle inspection. It is common to classify the magnetizing methods as either direct or indirect. With direct magnetization, current is passed directly through the component.Rubbing the nail with the permanent magnet causes a stronger, more lasting magnetism in the nail. For this to work, only one pole of the magnet must stroke the nail from one end to the other in a single direction. ... It usually takes around 20 to 30 strokes before the nail becomes sufficiently magnetized.

A permanent magnet needs to retain its magnetism (high retentivity) and resist demagnetization by external fields (high coercivity).

The coercivity of a substance is a measure of the reverse magnetising field required to destroy the residual magnetism of the substance.

At pole's horizontal component of earth's magnetic field is zero therefore, if needle is hold horizontally then it will stay in any position.

A freely suspended magnet rests in the geographic north-south direction.
Earth has two geographic poles, the North Pole and the South Pole. They are the places on Earth's surface that Earth's imaginary spin axis passes through. Our planet also has two magnetic poles, the North Magnetic Pole and the South Magnetic Pole just like a bar magnet. The magnetic poles are near, but not quite in the same places as, the geographic poles. The needle in a compass points towards a magnetic pole. Earth's North Magnetic Pole is actually the south pole of the Earth's geographic poles and vice-versa.
Hence, a freely suspended magnetic needle point in geographic north-south direction. The magnetic compass is the device that uses this principle. A magnetic compass contains a magnetic needle pivoted in a horizontal plane that indicates the direction of magnetic north at points on the earth's surface. It is an instrument that uses a magnetized steel bar to indicate direction relative to the earth's magnetic poles.

Statement A is false because null points are on the axial line when the north pole points north. Statement B is false because at the null point, the magnetic field of the magnet is equal and opposite to the horizontal component of the earth's magnetic field, not zero.

The best evidence is to test it by taking a direction compass and seeing it where the north position will point and you will see that it will always point to the north and south pole.