The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
In simple words, an electric current means the flow of charge. Charge carriers or moving electrons carry this charge in a wire. When we talk about current, we mean the movement of electrons to the positive battery terminal from the negative battery terminal through the circuit. The electric current is related to the resistance and voltage of the circuit.
Various instruments are used to measure electric currents. Here are a few-
When discussing electric current, we also come across the concept of direct current. It can be defined as the unidirectional flow of current or electric charge. There are various sources of direct current. These are semiconductors, conductors like wire, and even through the vacuum. The rate of flow of charge is referred to as electric current. Ampere is the SI unit for measuring the rate of electric charge flow. It is equal to a charge that flows through the same surface at one coulomb per second.
The direction of current is the direction in which the positive charge moves. Thus, the external circuit current moves away from the positive terminal towards the battery’s negative terminal.
Magnetism is defined as the characteristic of the collective electromagnetic force. It is related to particular phenomena occurring from the magnetic force. Magnetic fields are created by objects that attract or repel other objects.
The Earth’s Magnetic Field is also referred to as the geomagnetic field. The Earth also has a magnetic field that covers millions of kilometres into outer space. The planet looks like a bar magnet, with its south magnetic pole near the North Pole, and the magnetic North Pole is close to Antarctica. Although the Earth’s magnetic field extends to a great distance, it is weak in terms of magnetic field strength. The rotation of our planet on its axis results in electric currents forming a magnetic field extending around the planet.
The theory of the Dynamo effect explains the cause of Earth’s magnetism. As per this theory, the planet gets its own magnetic field lines due to the presence of metallic fluids present in its inner and outer core. Molten iron is present in the outer core, while solidified elements are present in the inner core. Nickel and molten iron present in the inner core create convection currents responsible for the generation of Earth’s magnetism. These currents have charged particles that generate magnetic fields.
In conclusion, this chapter discusses electricity and magnetism in detail. Both electricity and magnetism are important concepts in physics. An electric current means the flow of charge, whereas magnetism is defined as the characteristic of the collective electromagnetic force.