What is Electric Charge? Definition, Types & Examples

Charge is the most basic and fundamental quantity in electronics. Electric charge, basic property of matter carried by some elementary particles that governs how the particles are affected by an electric or magnetic field. And flow of charge around a circuit carrying energy from the battery (or power supply) is known as electricity. Electricity can flow only if there is a complete circuit from the battery through wires to components and back to the battery again.  The unit of electric charge in the metre–kilogram–second and SI systems is the coulomb and is defined as the amount of electric charge that flows through a cross section of a conductor in an electric circuit during each second when the current has a value of one ampere.

We say that electricity flows from the positive (+) terminal of a battery to the negative (-) terminal of the battery. We can imagine particles with positive electric charge flowing in this direction around the circuit. This flow of electricity is called conventional current and it is the direction of flow used throughout electronics. However this is not the whole answer because the particles that move in fact have negative charge, and they flow in the opposite direction! Let’s explore more about electricity and electric charge in this article.

1.    Definition of 1C

1 C can be defined as the charge flowing or travelling through a wire in one second if the current flowing through the wire is 1 A. One coulomb consists of 6.24 × 1018 natural units of electric charge, such as individual electrons or protons. From the definition of the ampere, the electron itself has a negative charge of 1.602176634 × 10−19 coulomb. An electrochemical unit of charge, the faraday, is useful in describing electrolysis reactions, such as in metallic electroplating. One faraday equals 96485.332123 coulombs, the charge of a mole of electrons (that is, an Avogadro’s number, 6.02214076 × 1023, of electrons).

2.    Fundamental Qualities of Electric Charge:  

Electric charges that are opposite one other tend to attract each other. Similar electric charges repel one another. They are as follows:

Two protons and two electrons, for example, repel each other. Protons and electrons have a strong attraction to one another. These characteristics are determined by the kind of charge or the force acting on them and coordinating flow direction. The type of charge they carry is different (note that protons have a charge of 1.6 x 10-19 C, while electrons have a charge of -1.6 x 10-19 C.). Although the proton and electron have the same charge, their natures are opposed. The charge sign is ‘q’ or ‘Q’. The number of electrons multiplied by the charge of an electron equals the total charge of electrons in an atom. The charge formula can be written as, according to this definition.

Q=ne

Where Q denotes total charge, e represents the charge on a single electron, and n denotes the total number of electrons. The charge of a body can be measured by comparing it to an expected value. According to a study, the charge of electrons is 1.6 x 10-19 C.

3.    Electric charges are of two types:

Positive Charge:

The charge of positive charges, or protons, is +1.6×10-19 Coulomb. The field lines with a positive charge emerge from within and extend to infinity.

Negative Charge:

The negative charges, or electrons, are -1.6×10-19 Coulomb. The field lines with a negative charge come from infinity.

Electric charges cause the hair strands to attract the ruler. Similarly, stroking a balloon on hair pulls hair to the balloon; but, if two balloons are touched simultaneously, the balloons will repel each other, but the hair strands will be attracted.

Electric current is the rate at which electric charges flow.

q/t = I

4.    Fundamental Properties of Electric Charge:

1) Electric Charge Additivity

When viewed as point charges, electric charges are scalar. It’s worth noting that while charges can be point charges, they’re still positive and negative charges. If there are n number of charges within, the overall charge will equal the algebraic sum of the individual charges, according to the additive property of electric charges.

Q = q1+ q2+ q3+ q4+ q5+ q6+ q7+ q8+ ….. qn

2) Conservation of charge:

According to the conservation of charges theory, charges are neither created nor destroyed. They can be moved from one body to another, but not formed or destroyed. Charges are always conserved in an isolated system.

3) Quantisation of charge:

A system’s charge is a fixed quantity. The charge is technically a quantised quantity. The integral multiples of the basic unit of charge (i.e. 1.6 x 10-19 C) can be used to indicate a system’s net charge. If the body’s net charge is q, the equation can be stated as:

Q = ne

The letter ‘e’ stands for the fundamental charge unit of electrons and protons. n must be an integer number in this formula; it cannot be a fractional or irrational value. As a result, any positive or negative integer can be used as the value of n. For instance, the value of n may be 1, -1, 2, -3, 4, -5, and so on.

The notion of electric charge quantisation is critical for calculating the total amount of electric charge contained in a system using the equation ‘q = ne.’ Consider a system with a total n1 number of electrons and a total n2 number of protons. Based on these facts, we may deduce that the total quantity of charge is (n2 – n1) e .

Conclusion:

When the matter is placed in an electromagnetic field, it acquires an electric charge, which causes it to experience a force. A positive or negative electric charge can exist (commonly carried by protons and electrons, respectively). Similar charges repel each other, while dissimilar charges attract each other.