So Field can be defined as the region in which, at each point there exists a corresponding value of some physical function.
Let us study What is this Electric Field?
We know that there are generally two types of charges existing in nature:
To generalize the definition of electric field considers that a very small test charge q0 is placed near to the object carrying much higher positive charge having value Q0.
Electric field or the strength of the electric field produced by the object having charge Q0 on the positive test charge q0 is defined as the Electric force per unit charge.
q0= Test Charge coming in the electric field.
Thus Electric field E is defined as ratio of the electric force acting on the positive test charge q0 and divided by the magnitude of the positive test charge.
Electric Field Equation
Fe is the electric force acting on the positive test charge,
q0 is the positive test charge.
Note that electric field considered above is produced by the charge which is external to the test charge q0 and not by the positive charge itself.
Electric field is the property of the source for example every electron come within its electric field.
The above formula is used in Calculating Electric Field at a point.
Electric Field Units
Unit of electric field will be N/C.
Electric Field Direction
F = Electrostatic force between two charges
d = distance between Q and q0
Q, q0 = Electrostatic charges.
ke = Coulomb constant.
According to the electric field formula
Thus Electric Field formula is given by
The Electric Field Strength produced by charge Q is given by
Electric Field Lines
They are nothing but a way of pictorially mapping the electric field around a configuration of charges. It is the curve drawn in such a way that the tangent to it at each point is in the direction of the net field at the point. An arrow on the lines of force is a must to indicate the direction of the electric field.
Electric Field Potential
Electric field potential or Electric Field Voltage at a point is equal to the electric potential energy of a charged particle at that location divided by the charge particle.
r is the distance between the charges
it is also termed as the Electric Potential or the Electrostatic Potential. The Unit of electric field potential is Joules per Coulomb.
Dipole Electric Field
The Formula for Electric dipole moment is given by
E= |qd|Where P is a vector quantity.
Direction of the electric dipole moment is from the negative charge to the positive charge present in the dipole. The field which is produced inside the dipole is given in the figure below.
In the figure shown below note that the electric field is shown in direction radially outward from the positive charge of the dipole and radially inward in case of the negative charge of the dipole.
Electric Field inside a Sphere
Hence we have
Q is the net charge on the sphere
r is the radius of the sphere.
Electric Field of a Wire
Electric Field Capacitor
This is the net electric field produced inside the capacitor charged plates.
Net Electric Field
Let us consider the following charges q1, q2, q3, ............. qn.
q = q1 + q2 + q3 + q4 + ...... +qn.
Uniform Electric FieldThe uniform electric field is the electric field which is not changing with respect to time. It is constant and not varying.
Consider the parallel plate capacitor, we could see the electric field is same at all point from positive end to the negative end.