Electric Field Intensity

The electrically charged particles give rise to a field of force around themselves. It is a physical field. If other charged particles exist in the physical field around the electric field, then the electric particles exert force on those charged particles. This force can either be an attractive force or a repellent force. The electric field intensity is a way to measure the strength of this physical field that surrounds the electrically charged particles. The intensity of the electric field is the force it can exert upon one unit of a positively charged particle placed inside the electric field.

Electric Field

The electric field is the physical field surrounding the electrically charged particles. However, fields not only originate from electric particles but also time-varying magnetic fields give rise to electric fields. Such an electric field is a vector quantity. It is the force per unit of charge exerted on a unit of positively charged particles placed around the electrically charged particles. This positive particle is assumed to be at rest. This charge on the positive particle is measured with the help of the electric field intensity. Let us take a look at what is electric field intensity and the electric field formula.

Electric Field Intensity

As we know, all electrically charged particles have electric fields associated with them. The electric field intensity is characteristic of this electric field.The strength of the electric field can be determined with the help of the electric field intensity. The force that a unit test positive charge experiences when placed in an electric field, is regarded as the electric field intensity. The electric field intensity is a quantity vector in nature which means it has direction as well as magnitude associated with it.The electric field intensity does not depend on the velocity of the charged particle placed in the electric field and also doesn’t depend on the mass of that charged particle. The only quantity it depends on is the quantity of force experienced by that particle. The test particle, in general, is a positive particle, but it can also be a negative particle.

The Electric Field Intensity Formula

Consider there is an electrically charged particle. Since this particle is charged, it leads to the formation of an electric field. Q is the source charge of this electric field. Now we need to know the strength or intensity of the electric field generated by the source charge Q. We can make use of another charged particle to determine this intensity. Suppose the charge we used to determine these is q, the test charge. A force F will be experienced by the test particle q. This force could be attractive or repulsive in nature. So, the electric field intensity is a ratio of force experienced by the test charge upon the charge of the test charge. The formula for electric field intensity is given below. Electric field intensity = Force/Charge In symbol its form, this can be represented as: E = F/q Let us derive a unit for electric field intensity. The formula of electric intensity is the ratio of force and charge. The standard unit of Force is Newton and the charge is generally measured in Coulomb. Hence the unit of electric field intensity will become Newton/Coulomb or N/C.

The Alternate Formula for Field Intensity

The formula for electric field intensity can also be had with the help of Coulomb’s law equation. Coulomb’s law equation tells that the electric force that exists between two charges is directly proportional to the multiplication of their charges. If the distance between the centres is squared, then the electric force that exists between them will be inversely proportional to the square of this distance. We apply this formula for the calculation of the electric field on our test charge q and source charge Q. So, the force will be equal to: F = (k * q * Q)/d² In this formula, k is constant whose value is equal to 9 × 10⁹ N.m²/C² The d here is the distance between the centres of these charges. Upon simplification, we get  the formula for electric field intensity as: E =(k × Q)/d²

The Inverse Square Law

This law depicts how a change in one variable in the formula can affect the other variables or the final result.The inverse square law states that there is an inverse square relationship between the electric field intensity and the distance between two charged particles. Symbolically, the inverse square law can be represented as given below: (E1 / E2) = d2²/ d2¹ Such is the electric field intensity and the formula for the same.

Conclusion

The force that exists around any electrically charged particle is the electric field. The strength of the ceiling field may vary. The electric field intensity is used to measure the strength of this field. Electric field intensity depends upon the force experienced by the charged test particle and the original charge of that test particle. The electric field intensity is regarded as the ratio of force upon charge. Hence, the unit of electric field intensity is Newton / Coulomb, and the dimensions are MLT^-3I^-1. The formula for electric field intensity can also be derived from Coulomb’s law equation.