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Electrical Formulas

Last updated date: 25th Feb 2024
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Electrical Formulae

The branch of physics that deals with electricity, electronics, and electromagnetic concepts, is known as electrical. Electrical formulae are very helpful in determining the value of a parameter in any electrical circuit. Voltage, current, power, resistance, and other electrical formulae are the most often used.

Understanding how the various units of electricity can work together can certainly help from a system of water pipes. Voltage represents water pressure, the current is represented flow rate, and resistance represents pipe size in this analogy. Ohm's Law, volts, amps, ohms, and watts are all significant fundamental components of electricity. According to Ohm's Law, the voltage is equal to the current flowing in a circuit multiplied by the resistance of that circuit. The base unit for measuring voltage is known as volts. The ampere, abbreviated as "amp" or "A," is the fundamental unit of electric current in the International System of Units.

Some commonly used electrical formulae are included below, and they may be useful to you.

Electric Field Formula

An electric field is a region created by an electric charge around it, the influence of which can be observed when another charge is introduced into the field's region.

The Electric Field formula is given by,

E = F/q


F = Force

q = Charge

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Potential Difference Formula 

The potential between two points (E) in an electrical circuit is defined as the amount of work (W) done by an external agent in moving a unit charge (Q) from one point to another. The potential difference formula is expressed as, 

E = W/Q


E =The electrical potential difference between two points.

W = Work done in moving a charge from one point to another.

Q = Quantity of charge in coulombs.

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Electric Power Formula

Electric power may be defined as the rate at which work is completed. The watt is the SI unit for power and is written as P. The time, voltage, and charge are all connected by the power formula. Ohm's law can be used to change the formula. The formula of electric power is as follows:

P = VI

The formula of electric power in term of Ohm’s law is as follows,

P = I2R


P = V2/R


Q= Electric charge

V= Voltage

t= Time

R= Resistance

Electric Potential Formula

The charge possessed by an object and the relative position of an object with respect to other electrically charged objects is the two elements that give an object its electric potential energy.

When an item moves against an electric field, it gains energy that is known as electric potential energy. The electric potential is calculated by dividing the potential energy by the quantity of charge for any charge.

The electric potential energy formula at any point around a point charge is given by:



V = Electric potential energy

q = Point charge

r = Distance between any point around the charge to the point charge

k = Coulomb constant; k = 9.0 × 109 N

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Electric Flux Formula

The electric flux is the total number of electric field lines passing through a given area in a given period of time.

The electric flux formula is expressed as,

𝜑p = EA

When the same plane is tilted at an angle ϴ, the projected area is Acosϴ, and the total flux through the surface is:

𝜑 = EA cosƟ


E = Magnitude of the electric field.

A = Area of the surface.

Ɵ = Angle made by the plane.

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Electric Current Formula

An electric current is the constant flow of electrons in an electric circuit. When a potential difference is applied across a wire or terminal, electrons move. The rate of change of electric charge via a circuit is known as electric current. This current is equal to the circuit's voltage and resistance. The symbol for it is I, and the SI unit is Amperes. The electric charge and the time are related to the electric current.

The electric current formula, according to Ohm's law, will be,



V = Voltage

R = Resistance

I = Current

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Electric Charge Formula

Electric Charge is the property of subatomic particles that causes to experience a force when placed in an electromagnetic field. The S.I unit of electric charge is coulomb and the symbol is Q. The electric charge formula is given by,

Q = I x t

Q = Electric Charge

I = Electric current 

t = Time

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Solved Examples

Ex.1. A Wire Carrying a Voltage of 21 Volts is Having a Resistance of 7⍵. Calculate the Electric Current.


Given: Voltage = 21 V,

Resistance R = 7 ω

The electric current formula is,



I = 3 Amperes

Hence electric current is 3 Amp.

Ex.2. A force of 13 N is Acting on the Charge at 9 μ C at any Point. Determine the Electric Field Intensity at that Point.



Force F = 13 N

Charge q = 9 μ C

Electric field formula is given by



E = 1.45 10-6 N/C

Ex.3.  If The Current And Voltage of An Electric Circuit Are Given As 3.5A And 16V Respectively. Calculate The Electrical Power?


Given measures are,

I = 3.5A and V = 16V

The formula of electric power is,

P = VI

P = 16 × 3.5 = 25

P = 56 watts.

FAQs on Electrical Formulas

1. What is the Work Formula?


The work is equal to the force times the distance is given by,

W = fd

If the force is being exerted at an angle to the displacement, the work done is,

W= fd cosӨ

2. What are Types of Current?

Answer: Direct current (DC) and alternating current (AC) are the two types of current electricity.

Electrons travel in one direction with direct current. Direct current is generated batteries. Electrons flow in both directions in alternating current.

3. What are Voltage and Current?

Answer: The difference in charge between two points is known as voltage. The rate at which charge travels is known as current.