Electric Field Formula

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What is the Electric Field Formula?

The electric field is the region around an electric charge where its influence can be observed. The existence of an electric field can be experienced when another charge is brought into the field. According to the incoming charge’s nature, the electric field will either attract or repel the charge. The electric field can be considered as a property of any electric charge. The electric field strength or intensity is defined by the charge and electrical force acting in the field.

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If the charge is denoted by q and the force experienced by it is denoted by F, then the direction of the Field lines is determined by both F and q.

What is The Electric Field Formula?

The Electric field formula is

E = F/q

Where E is the electric field

F (force acting on the charge)

q is the charge surrounded by its electric field.

If two charges, Q and q, are separated from each other by a distance r, then the electrical force can be defined as

F= k Qq/r2

Where F is the electrical force

Q and q are the two charges

R is the distance of separation of the two charges

K is Coulomb’s constant.

Therefore, electric field E can be defined as

E = F/q

or, E = k Qq/r2q

This is the electric field experienced by charge Q due to charge q.

Coulomb’s law defines this electric field intensity formula.

Again, if a voltage V exists across a distance r, then the electric field is defined as

E= V/r

The SI unit of an Electric field is N/c or Newton/Coulomb.

If multiple electric fields exist in a region, then all the electric fields add up vectorially, i.e., keeping the field’s direction into consideration.

The following electric field strength formula gives the resultant electric field existing in that place:

Fig. Formula of resultant electric field existing due to several electric fields existing in the same location.

Application of Electric Field

The concept of the electric field has several applications. Some of them include:

  • Electroporation- electroporation is an invasive technique where electric fields are used to make pores in cell membranes to insert drugs, medicines, or genes. It is widely used in cloning processes.

  • It is used to study tissue dynamics.

  • The electric field is used to control different crystallization processes like nucleation, crystal growth, etc.


The electric field is the region surrounding a charge where its force can be experienced. The nature of the charge determines the direction of the field. Coulomb’s law describes the formula for electric fields. The electric field has several applications for research and industrial purposes.

FAQ (Frequently Asked Questions)

1. What is the electric field intensity for a force of 30 N acting on a charge of 6 C?

Force applied (F) = 30 N

Charge (q) = 6 C.

According to Coulomb’s law,

Electric field E = F/q

Therefore, E = 30/6 = 5 N/C.

2. Calculate the electric field’s strength for a voltage of 45 V across a distance of 5 cm.

Voltage (V) = 45 V

Distance (r) = 5 cm

Electric field E = V/r

Therefore, E = 45/5 = 9 V/cm

3. State some biological uses of the Electric field.

The electric field has implications in several biological experiments. It is widely used in electroporation techniques to introduce new drugs, genes, etc., into the cell. Such a technique is used for cloning. The electric field is used to study tissue dynamics. It is also used in the protein crystallization process like nucleation, crystal growth, the study of crystal dynamics, etc.