Electric Charges and Fields

When matter is positioned in an electromagnetic field, electric charge is the physical attribute of matter that causes the other matter to sense a force. Charge, electrical charge, and electrostatic charge are all terms used to describe electric charge. The symbol ‘q’ is used to represent it. Because charge has simply magnitude with no relation to direction, it is a scalar quantity. In nature, there are two types of charges: positive charge and negative charge. Charges of the same nature repel each other, while charges of opposite nature attract each other. The integrated field of electromagnetism includes both electricity and magnetism as components.

Electric field

• Electrostatic force exists between two point charges in open space/medium.
• It indicates that one charge has an effect on another in space.
• As a result, an electric field exists in the region surrounding a charged particle or charged body in which an additional charge is added, causing electrostatic force.

Electric field intensity (E)

• In both magnitude and direction, the electric field intensity at a point equals the electrostatic force experienced by a unit positive point charge.
• The force experienced by a test charge qo as a result of certain charges (called source charges) put at a point in an electric field is F, and the electric field intensity at that point as a result of source charges is E = Fqo.
• Suppose E is to be determined practically. In that case, the test charge qo must be minimal, or the charge distribution on the source that produces the electric field will be affected, changing the quantity to be measured.

Properties of electric field intensity

• It is a quantity with a vector. It has the same direction as the force experienced by positive charges.
• The positive charge causes the electric field to point away, whereas the negative charge causes it to point towards it.
• Newton/Coulomb is the SI unit for it.
• [MLT-3A-1] is the dimensional formula.
• F=qE is the electric force on a charge q placed in an electric field region at a position where the electric field intensity is E.
• On a positive charge, the electric force is in the same direction as the electric field, while it is in the opposite direction on a negative charge.

• According to the superposition principle, the field intensity at a point due to a system of charges is the vector sum of the field intensities due to individual point charges.

            E=E1+E2+E3+…

• Source charges are responsible for the creation of the electric field. Unless we change the distribution of source charges, the electric field will remain constant at a given site.

Electric charge

Electric charge is the property of matter that causes electromagnetism (electrical and magnetic phenomena). A charge is a determined proportionality constant measured in Coulomb units. Electrons, protons, and -particles are examples of naturally occurring charged particles.

Properties of charge

• As charge is a scalar quantity, it sums up algebraically and signifies electron excess or deficiency.
• There are two categories of charges: positive and negative. 

• Trying to charge a body is the process of transferring charge (electron) from one medium to another. When a positively charged substance loses electrons, it results in an electron deficit. A surplus of electrons exists in a negatively charged body. This also demonstrates that a negatively charged medium has a larger mass than a positively charged medium of a similar mass.
• In an isolated system, total charge (the sum of positive and negative charges) remains constant since charge cannot be created or destroyed; it can only be transferred from one entity to another.
• Charge exists in integral multiples of a basic unit of electrical charges on any medium, and hence, it is approximated.
• This unit represents the measure of an electron’s charge (1e = 1.6 × 10-19 C). Millikan’s oil drop experiment demonstrated charge quantisation or atomicity.
• As a result, the charge is applied to a body by,

Q=ne, where n is the number of electrons or protons and e is the electron’s charge.

Conclusion

Recently, components with the charge e3 and 2e3 have been proposed. These components are known as quarks. A charge is always related to mass, i.e., the charge cannot exist without mass, although mass can exist without the presence of charge. A particle that has no mass, including a photon or neutron, can never possess the properties of charge. A charge is relatively unchanging; it is unaffected by the frame of reference, i.e., a charge on a body has no effect on its speed. This feature is significant because, unlike charge, a body’s mass is proportional to its speed and grows as speed increases.