The Wonder of Electricity

Electricity is the set of physical phenomena associated with the presence and flow of electric charge. Electricity gives a wide variety of well-known effects, such as lightning, static electricity, electromagnetic induction and electrical current. In addition, electricity permits the creation and reception of electromagnetic radiation such as radio waves.

Assignment starts Here Question 1

In electricity, charges produce electromagnetic fields which act on other charges. Electricity occurs due to several types of physics:

• electric charge: a property of some subatomic particles, which determines their electromagnetic interactions. Electrically charged matter is influenced by, and produces electromagnetic fields.
• electric field (see electrostatics): an especially simple type of electromagnetic field produced by an electric charge even when it is not moving (i.e., there is no electric current). The electric field produces a force on other charges in its vicinity.
• electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.
• electric current: a movement or flow of electrically charged particles, typically measured in amperes.
• electromagnets: Moving charges produce a magnetic field. Electrical currents generate magnetic fields and changing magnetic fields generate electrical currents.

In electrical engineering, electricity is used for:

• electric power where electric current is used to energize equipment;
• electronics which deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies.

Electrical phenomena have been studied since antiquity; though progress in theoretical understanding remained slow until the seventeenth and eighteenth centuries. Even then, practical applications for electricity were few, and it would not be until the late nineteenth century that engineers were able to put it to industrial and residential use. The rapid expansion of electrical technology at this time transformed industry and society. Electricity’s extraordinary versatility means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. Electrical power is now the backbone of modern industrial society.

When beginning to explore the world of electricity and electronics, it is vital to start by understanding the basics of voltage, current, and resistance. These are the three basic building blocks required to manipulate and utilize electricity.

At first, these concepts can be difficult to understand because we cannot “see” them. One cannot see with the naked eye the energy flowing through a wire or the voltage of a battery sitting on a table.

Even the lightning in the sky, while visible, is not truly the energy exchange happening from the clouds to the earth, but a reaction in the air to the energy passing through it. In order to detect this energy transfer, we must use measurement tools such as multimeters, spectrum analyzers, and oscilloscopes to visualize what is happening with the charge in a system. Fear not, however, this tutorial will give you the basic understanding of voltage, current, and resistance and how the three relate to each other.

Georg Ohm