In today's world, familiarity with the basics of physics and electricity seems essential to all members of society. Here are some words or terms which you may have heard or seen in your daily activities or work:
1- Atom: is the basic unit of matter.
Note1: Atoms consist of protons, electrons and neutrons. Protons (positive charge) and the neutrons (zero charge) are located in centre (nucleus) and electrons (negative charge) distributed in electronic shells around them.
2- Molecule: Two or more atoms join together and form molecule.
3- Electric charge (Q): is the physical property of elementary particle of matter.
- Coulomb (C): is a unit of electric charge.
- 1 Coulomb = 6.24 x 1018 electrons
- Negative: carried by electron
- Positive: proton is considered as positive
- Zero: neutron is neutral
4- Ion: is a particle (atom or molecule) with net electric charge (one or more positive or negative electrical charges)
- Cation: positively charged ion
- Anions: negatively charged ion
5- Electric Current (I): is the flow of electrons through a conductor.
- Ampere (A): is a unit of electric current and refers to the number of charges (Q) that move through the conductor per second (t).
- I = Q / t
- 1 Ampere = 1 Coulomb / 1 Second = 6.24 x 1018 electrons per second
6- Electric Voltage (V): is a pressure which pushes the electric charges (Q) to move through a conductor. This pressure is an electric potential between two points of conductor which applied by an external electric force.
- Volt (V): is a unit of electric voltage.
7- Electric Resistance (R): is a measure of the opposition to flow of electrons in a conductor. Resistance is a similar to friction in water pipes.
- Ohm (Ω): is a unit of electric resistance.
- R = V / I
8- Electric Energy (W): is the energy which generated due to movement of electric charges (Q) due to electric potential (V) in a conductor
- Joules (J): is a unit of electric energy
- W = V x Q = V x (I x t) = (V x I) x t = P x t
- Electrical energy is measured in KWh.
9- Electric Power (P) or Wattage: is the rate of transmission (generation or consumption) of electric energy (W) per unit time (t)
- Watt (W): is a unit of electric power.
- P = W / t
- P = V x I
- Watt = Joule / Second = Volt x Ampere
10- Direct Current (DC): electric charges (Q) flow through a conductor in one direction or in other words there is a current (I) only in one direction between two points of conductor.
11- Alternating Current (AC): direction and magnitude of current (I) and flow and amount of electric charges (Q) changes periodically during the time.
12- Electrical frequency (f): is a number of changing the direction of current (I) per second in alternating current (AC)
- Hertz (Hz): is a unit of frequency
Leave a Reply