Electromagnetism

Electromagnetism is defined as a phenomenon in which a magnetic field is generated with the help of the current in the conductor. Electromagnetism is made of two different aspects - electricity and magnetism. Electricity and magnetism were considered as different and separate forces up until the 19 th century. After more research, they were regarded as interrelated phenomena due to Einstein’s Special Theory of Relativity. With the help of this theory we can understand that even though both electricity and magnetism possess varying properties, they are still defined by one common phenomenon. Electric charges help produce electric forces at rest or while in motion. Meanwhile, magnetic forces can only be formed when there exists a motion of charged particles.

Electrical phenomena is highly capable of occurring even on neutral matters due to the fact that the forces can easily act on individually charged constituents. This force is accountable for many of the chemical and physical characteristics of both atoms and molecules. In comparison with gravitational force, electrical force is significantly stronger. For instance, electric force is responsible for the generation of lightning and thunder along with the creation of various storms.

Electric forces are found in regions called electric fields whereas magnetic forces are found in magnetic fields. These fields are essential in nature and can be present in space quite far from the charges. Electrical fields are capable of creating magnetic fields and vice versa. This can be seen independent of external charges.

Main Properties of Electromagnets

• Electromagnets are made of soft iron core
• The nature of an electromagnet is temporary
• The field strength of an electromagnet can be easily changed
• The demagnetization of electromagnet is simply done by switching the current off
• It is possible to reverse the polarisation process

Principle of Charge Conservation

Same as Coulomb’s law, the importance of the Principle of Charge Conservation is significant. The principle talks about the charge of the system which is isolated (can also be stated as a separate system) and cannot be changed. In case if there is any particle which is positively charged inside the system, then it produces a particle which is negatively charged with the same magnitude while maintaining the principle of conservation of charge. Naturally, whenever a highly radiated energy comes in contact with matter, they form a pair of oppositely charged particles. Due to this process, a positron and an electron are also created. This process is termed as pair production.

Electric Fields and Forces

The values of an electric field at a certain point are the same as the force which can be put forth in unit charge at a specific position in space. All the charged particles arrange an electric field in its surrounding space. The presence of this electric field can be easily felt by a 2 nd charge. It is clearly proven that the 2 nd charge either attracts the initial charge or repels it. This attraction or repulsion is entirely based on the signs of these two charges. As the 2 nd charge contains an electric field like the 1 st one, the 1 st charge is capable of feeling the presence of the 2 nd charge. It either attracts or repels it as well.

Magnetic Fields and Forces

Magnetic force can influence the charges which are in motion and not the ones which are at rest. This force can be transmitted by a magnetic field. The understanding of both magnetic fields and forces are quite complicated in comparison with the electric fields and forces. The pointing of the magnetic field is not along the source direction of the field but the pointing direction is towards perpendicular motion. Apart from that, the magnetic force acts perpendicular to the magnetic field. Contrastingly for electric force, it is being pointed towards or away from the charge in a direct manner.

Applications of Electromagnetism

The following are some of the basic applications of electromagnetism:

• Electromagnetism provides an essential working principle for many of our home appliances that we use in our day to day life.
• High speed trains or Maglev trains use electromagnetism as a working principle for a certain number of body parts.
• Communication systems use electromagnetism in the form of electromagnetic radiation in order to transfer and receive the data through a certain source.
• These radiations are capable of transmitting energy in vacuum or without using any medium at all.
• In factories and industries, electromagnetism is an essential phenomenon used in production stages of everything from small components to larger, more complicated devices.