Dimensional Formula of Current

There are various metals present on earth having free electrons but they do not induce current on their own because of the randomly equal and opposite movement of the electrons which counter each other. The drift of the electrons in a specific direction leads to the flow of current in a circuit; this drift is caused due to the potential difference between two points. The electron movement continues from higher to lower concentration of potential difference (the electron flow is from negative to positive points, but the current flow is positive to negative if the circuit is induced with a battery). 

Current and Voltage Relationship

Current has a very interdependent relationship with voltage as an electric current is generated by the movement of electrons within a conducting material or conductor. Voltage (also known as the potential difference, which drives electron drift) is the amount of force necessary to drive current flow through a conductor.

Current and Resistance 

Current flow is the result of electron drift in a circuit, whereas resistance is an opposing force to the flow of electrons, thus hampering the flow of current. The circuit with higher resistance will induce less current and vice versa (both are inversely proportional). Ohm’s law justifies the relationship between resistance and current, i.e., I = (V) / (R) 

Flow of Current

A circuit with a battery or an energy source to build up the voltage is essential to ensure the flow of current. The electrons at first move randomly, and due to this, they can produce the current. Integrated circuits, from which electrons flow in a single line, remain closed when switched on from the outside.

An electric current can produce electromagnetic fields that are further utilised in generators, transformers, inductors and motors. However, with the voltage, they move in a single direction from high to low energy and provide proper electric current. 

Unit

The electric current formed in the integrated circuits is measured with the help of coulombs per second. However, the SI unit of electric current is Ampere, which is denoted by the letter ‘A.’ The ampere is further identified as one coulomb of charge that travels in one second past one point. For instance, if there are 6.241 x 1018 electron flows in one second, the electrical current in the integrated circuits will be 1 A. Also, there are wide varieties of ampere uses, including milliamp with 0.001 A, micro amp with 0.000001 A, etc. 

Dimensional Formula of Current 

Current = (Electric Charge)/(Time)

•  I = Q / T

Where, 

• Q has the unit coulomb, T has the unit of second and I has the unit of ampere.

Therefore, 

• Ampere = Coulomb / Second 

• Current is defined as the rate of flow of charge for every unit of time.

The dimensional formula of current is written as:

[M0L0T0I1]

where, M: Mass; L: Length; T: Time; I: Current

Dimensional Formula

In terms of dimensions, a dimensional formula is an equation that expresses the relationship between fundamental and derived units (equation). The letters L, M and T are used to represent the three basic dimensions of length, mass and time in mechanics.

All physical quantities can be stated in terms of the fundamental (base) units of length, mass and time, multiplied by some factor (exponent).

The dimension of the amount in that base is the exponent of a base quantity that enters into the expression.

The units of fundamental quantities are expressed as follows to determine the dimensions of physical quantities:

• ‘L’ stands for length, 

• ‘M’ for mass, and 

• ‘T’ for time.

Example: The area is equal to the sum of two lengths. As a result, [A] = [L2]. That is, an area has two dimensions of length and zero dimensions of mass and time. In the same way, the volume is the sum of three lengths. As a result, [V] = [L3]. That is, the volume dimension has three dimensions: length, mass and time.

Conclusion

The electric current is a result of the flow of electron drift in a circuit that opposes the force like resistance. The current flow in a circuit has various effects like heat effect, chemical effect, magnetic effect, etc. The electric current shares rules of inverse proportionality with resistance and interdependent relation voltage defining the decrease or increase in the amount according to fluctuating values of the other two quantities respectively. The dimensional formula of current reflects the fundamental units of the electric current describing its SI unit, i.e., ampere = electric charge per unit second of time.