What is electric field

Electric field

Today this article will teach you about electric field with the easiest way. Before learn about electric field, we have to learn about force, electric force, electromagnetic force, properties of charge and Newton’s law. Let’s start…..

Force is an external cause which can be changes or tends to change the state of rest or of motion of a body is called force. So, force is a pull or push. We can’t work without forces; we have learned it on mechanics.

What is electric force

It’s clear to us that electric force is happen between two charged particles. And charge particle can be negative or positive. So the electric force can be attractive or can be repulsive. If both of charge particles become positive then there will be repulsive force and the both charge become opposite one another, then the force will be attractive. We can measure the magnitude of electric force by Coulombs law. Coulombs law state that the force between two charge particles is proportional to the product of the charges particles and anti proportional to the square if distance between the two charged particles.

 then, F = q₁q₂  / r²

Where q₁ and q₂ are the magnitude of charges and r is the distance between two charges.

We will discuss about electric force details on other article but I will discuss you today about electric field. You have learnt about gravitational force and gravitational field. What was that? The space around an object in which its gravitational force or gravitational attraction felt is called gravitation field.

 

Same concept we can use to determined the definition of electric field. So, a charged particle can impact a definite region by electric force and that region will be called electric field.

Electric field definition

The electric field E at point in space is defined as the electric force F_e acting on a positive test charge q_ₒ placed at that point divided by the magnitude of the test charge. Mathematically,

SI unit of the electric field is N/C.

So, we have cleared now the electric field is a property of a charged particle. And it’s depend upon on the electric force and the charge particle. If the magnitude of the charge becomes larger then electric field will be less.

Direction electric field

To determine the direction of an electric field, consider a point charge q located a distance r from a test charge q_ₒ located at a point P, as shown in figure 1.00 ( a ) According to Coulomb’s law, the force exerted by q on the test charge is,

figure 1.00

 

 

Where, ȓ is a unit vector directed from q towards qₒ. Because the electric field at P, the position of the test charge, is defined by we find that at P, the electric field created by q is,

So, we can calculate electric field from the above equation. Then at any point P, the total electric field due to a group of charge will be the sum of electric field of individual charge.

ELECTRIC FIELD OF A CONTINUOUS CHARGE DISTRIBUTION

In this system charges are distributed all over the conductor. Do you know what is conductor? I am not talking about the profession of person. In physics, conductor is a material which allowed passing charges (electric current) in any direction. Insulator is a not conducting material. We can also calculate Electric field for continuous charge distribution. We can divided the hole charged body by small element then calculate electric field for each small element t hen the vector sum of all the small electric field will be the final result. We will calculate electric field for some different type of object.

What is charge density

Charge density is defined as the amount of charge in a unit area. For a line charge, the charge density is defined as the amount of charge of unit length. So, we can calculate charge density for linear or surface or volume.

If the charge Q distributed uniformly over the volume V then the volume charge density  will, ρ = Q/v

If the charge Q distributed uniformly over the surface S then the surface charge density will, Q/S

 

If the charge Q distributed uniformly along a line l then the charge density will be Q/l

If the charge is not uniformly distributed over a volume, surface, or line, we have to express the charge densities as Q/V, Q/S or Q/l respectively.

Electric field line is imaginary lines drawn through a region or empty space. The tangent of the lined indicates the direction of the electric field. Electric field for a point charge: 1) if the point charge positive then the electric field lines gradually outward. 2) if the point charge negative then the direction of electric field gradually inward. So, it’s clear that electric field line start with positive charge and end with negative charge and no two lines cross each other.

MOTION OF CHARGED PARTICLES IN A UNIFORM ELECTRIC FIELD

Do we know what motion is? Motion is defined as the changes of position of a body in unite time. So, motions of a charge particle also mean that. For giving motion to a body you have to give force. When a particle of charge q and its electric field E then the force exerted on this charge particle become F = qE. If this force give acceleration a to that point then we can say

F_e = qE = ma

So, a = qE/m

 If the charge particle be positive then the direction of acceleration and electric field line will be same. And if the charge particle be negative then the direction of acceleration and the electric field line will be opposite.

 

 

So what we learn about electric field?

• It’s a property of charge particle. 
  It direction depend on the nature of charge. 
  The electric field line starts with positive charge and end in the negative charge. The electric field lines never cross one another. 
  
  
  
  
   That’s for today. Comment below what type of article you want?