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Dimensions of Coulomb: The coulomb is an electric charge unit derived from the SI system. It was previously described as the charge given in one second by an electric current of one ampere, with an ampere defined as the current required to generate a magnetic force of 0.2 micronewtons per meter between two parallel wires 1 meter apart.

**A brief outline**

A charge of 1 C has the same magnitude but the opposite sign as a charge of the same number of electrons. The coulomb is one of the few SI units that is determined solely by the value of one of the SI defining constants. Despite this, the coulomb is still categorized as a derived unit, whereas the ampere is still classified as a SI base unit, which is quite contradictory.

**Important concepts**

The Coulomb (commonly abbreviated as ‘C’) is a unit of electric charge used in physics. One Coulomb of charge is equal to the charge transferred by an electric current of constant magnitude in one second of time, according to the International System of Units (commonly abbreviated to SI). It’s also the amount of excess charge that builds up in a one-farad capacitor when it’s charged to a one-volt potential difference.

**Dimensional Formula of Coulomb**

The dimensional formula of Coulomb is:

**[M ^{0} L^{0} T^{1} I^{1}]**

M = Mass, I = Current, L = Length, T = Time

**Derivation**

Coulomb is the SI unit of electric charge. Thus, the dimensional formula of Coulomb is the same as that of the electric charge.

Since, electric charge (Q) = current × time – (1)

The dimensional formula of,

**Current = [M ^{0} L^{0} T^{0} I^{1}] – (2)**

**Time = [M ^{0} L^{0} T^{1}] – (3)**

On replacing equation (2) and (3) in equation (1)

**Meanwhile, electric charge (Coulomb) = current × time**

**Coulomb = [M ^{0} L^{0} T^{0} I^{1}] × [M^{0} L^{0} T^{1}] = [M^{0} L^{0} T^{1} I^{1}]**

So, Coulomb is dimensionally denoted as [M^{0} L^{0} T^{1} I^{1}].

**Significance of dimensions of coulomb in IIT JEE exam**

It is critical to take a holistic approach to every facet of a subject’s chapter. It will not only adequately prepare you for the exam, but will also clarify your understanding of each topic. It will help you pass the JEE exam’s conceptual problems. The number of questions from the chapter unit and dimensions would be one or two, with a weightage of roughly four marks.

## FAQs

##### What does the term dimension signify in Physics?

It is a formula that connects derived and fundamental quantities. It has nothing to do with the magnitude of the resulting quantity, though.

##### What are some of Coulomb's Laws applications?

Calculate the force between the two charges as well as the distance between them.

##### What does Coulomb's law mean when it says absolute permittivity?

Absolute permittivity is the measure of resistance encountered when an electric field is created in a medium in electromagnetism.