Home Physics Magnetism and Matter

Magnetism and Matter

Current loop as a magnetic dipole and its magnetic dipole moment, magnetic dipole moment of a revolving electron, magnetic field intensity due to a magnetic dipole (bar magnet) along its axis and perpendicular to its axis, torque on a magnetic dipole (bar magnet) in a uniform magnetic field; bar magnet as an equivalent solenoid, magnetic field lines; earth's magnetic field and magnetic elements. Para-, dia- and ferro - magnetic substances, with examples. Electromagnets and factors affecting their strengths, permanent magnets.

Permanent Magnets and Electromagnets

Permanent Magnets and Electromagnets

Substances which at room temperature retain their ferromagnetic property for a long period of time are called permanent magnets. Permanent magnets can be made...
Ferromagnetic Substances

Ferromagnetic Substances

Ferromagnetic substances are those which develop strong magnetization in the direction of the magnetizing field. They are strongly attracted by magnets and tend to...
Diamagnetic Substance

Diamagnetic Substance

Diamagnetic substances are those which develop feeble magnetization in the opposite direction of the magnetizing field. Such substances are feebly repelied by magnets and...
Paramagnetic substance

Paramagnetic Substance

Paramagnetic substances are those which develop feeble magnetization in the direction of the magnetizing field. Such substances are feebly attracted by magnets and tend...
Earth’s magnetic field and magnetic elements

Earth’s Magnetic Field and Magnetic Elements

A freely suspended magnetic needle at a point on Earth comes to rest approximately along the geographical north-south direction. This shows that the Earth...
The magnetic field lines

The Magnetic Field Lines

The magnetic field lines are a visual and intuitive realization of the magnetic field. Electric field lines of an electric dipole are also displayed...
Bar magnet as an equivalent solenoid

Bar Magnet as an Equivalent Solenoid

To demonstrate the similarity of a current carrying solenoid to a bar magnet, let us calculate axial field of a finite solenoid carrying current. Consider:...
Torque on a bar magnet placed in a uniform magnetic field

Torque on a Bar Magnet Placed in a Uniform Magnetic Field

Consider a bar magnet NS of length 2l and pole strength m placed in a uniform magnetic field of induction B at an angle θ...
Magnetic Field Intensity due to a Magnetic Dipole

Magnetic Field Intensity Due to a Magnetic Dipole

Magnetic field intensity at a general point having polar coordinates (r,θ) due to a short magnet is given by Special Cases: At axial point θ...
Magnetic dipole moment of a revolving electron

Magnetic Dipole Moment of a Revolving Electron

According to Neil Bohr’s atom model, the negatively charged electron is revolving around a positively charged nucleus in a circular orbit of radius r....