Electromagnetism, a science of charge and of the forces and fields related to charge. Electricity and magnetism are 2 aspects of electromagnetism.
In modern life is pervaded by electromagnetic waves phenomena. When we switch on the lightbulb, the current flows through a thin filament in the bulb, and the filament gets heated because of the current flow to such a high temperature that it glows, illuminating its surroundings. In the Electric clocks and connections link simple devices of this kind into complex systems such as traffic lights monitoring that are timed and synchronized with the speed of vehicular flow. The communication devices like Radio and television sets receive information carried by electromagnetic waves traveling through space at the speed of light. To start an automobile such as a motor, currents in an electric starter motor generate magnetic fields that rotate the motor shaft and drive engine pistons to compress an explosive mixture of gasoline and air; the spark which gets initiated to form the combustion is an electric discharge, which makes up a momentary current flow.
(i) An electromagnet is temporary in nature.
Like Coulomb’s law, the principle of charge conservation is a very fundamental law of nature. According to the principle, the charge of an isolated system (separate system) cannot change. If another positively charged particle appears within a system, a particle with a negative charge of the same magnitude (value) will be created at the same time; thus, the principle of conservation of charge is maintained. In nature, a pair of oppositely charged particles are formed when high-energy radiation interacts with matter; an electron and a positron are formed in this process known as pair production.
The value of the electric field at a particular point in space, for example, equals the force that would be exerted on a unit charge at a particular position in space.
The magnetic force influences only on those charges that are already in motion (moment) and this is transmitted by the magnetic field. Both the magnetic fields and magnetic forces are more complicated to understand than electric fields and electric forces. The magnetic field doesn't point along the direction of the source of the field; rather, it points in a perpendicular direction. In addition, the magnetic force acts in a direction that is perpendicular to the direction of the magnetic field. In comparison, with both the electric force and the electric field which points directly towards or away from the charge.