Electromagnetism vs Magnetism
Electromagnetism and magnetism plays an important role in our daily lives. Phenomena such as electron – nucleus bond, interatomic bond, intermolecular bond, electricity generation, sun light and almost everything in day to day life except for the gravity is based on electromagnetic theory.
Magnetism occurs due to electric currents. A straight current carrying conductor exerts a force normal to the current on another current carrying conductor placed parallel to the first conductor. Since this force is perpendicular to the flow of charges, this can’t be the electric force. This was later identified as magnetism. Even the permanent magnets we see are based on the current loop created by the spin of the electron.
The magnetic force can be either attractive or repulsive, but this is always mutual. A magnetic field exerts a force on any moving charge, but the stationary charges are not affected. A magnetic field of a moving charge is always perpendicular to the velocity. The force on a moving charge by a magnetic field is proportional to the velocity of the charge and the direction of the magnetic field. A magnet has two poles. They are defined as the North Pole and South Pole. In the sense of magnetic field lines, the North Pole is the place where a magnetic field line starts and the South Pole is the place where it ends. However, these field lines are hypothetical. It must be noted that magnetic poles does not exist as a monopole. The poles cannot be isolated. This is known as the Gauss’ law for magnetism.
Electromagnetism is one of the four basic forces in nature. Other three are weak force, strong force and gravity. Electromagnetism is the unison of electric fields and magnetic fields. Electric charges have two forms; positive and negative. In the sense of electric field lines, the lines start at positive charges and end at negative charges. The theory of electromagnetics suggests that changes in electric fields creates magnetic fields and vice versa. The magnetic field created by the changing electric field is always perpendicular to the electric field and is proportional to the changing rate of the electric field and vice versa. James Clark Maxwell was the pioneer in postulating the electromagnetic theory. The electric theory and magnetic theory was developed separately by other scientists and Maxwell unified them. One of the greatest achievements of Maxwell was the prediction of speed of electromagnetic waves and thereby light. Electromagnetism plays a vital role in almost everything in day to day life.
What is the difference between Electromagnetism and Magnetism?
• Electromagnetism, as the name suggests, consists of electricity and magnetism.
• Magnetism can be considered as a sub phenomenon of electromagnetism.
• Magnetism only discusses the magnetic fields. Electromagnetism discusses both time variant magnetic fields and time variant electric fields.
• Electromagnetism is a fundamental force of nature while magnetism alone is not.
• Electric monopoles can exist while magnetic monopoles do not.
• A magnetic field always require an electric current while an electric current will always generate a magnetic field.