Learning About the Electric Field

The value of E – also called field strength, electromagnetic field intensity or simply the electric field – represents the size and orientation of the electric field. To anticipate what would happen to electrostatic force near a spot, all that is necessary is a comprehension of the size of the electric field at a particular location but no accurate understanding of what caused the field. Rather than seeing the electrostatic charge as simple contact between two remote electrostatic forces, one charge is seen as the base of an electric field that expands into the external environment. Electric field due to a system of charges intensifies at the same point. The physical significance of the electric field aids in understanding polar molecule applications and behaviour.

Strength of Electric Field

To compute the intensity of an electric field E, use the electric (or Coulomb) force F produced per unit positively electrically charged q at every location, or simply E = F/q. 

If the second charge is two times higher, the force acting doubles, yet their quotient, the measurement of the electric field E, does not change at any given place. The supply charge controls the intensity of the electric field, not the test charge.

The electric field is stronger when the field lines are closer than farther apart. The size of the electric field around an electric charge, regarded as the source of the electric field, is determined by the charge’s spatial distribution. The electric field is directly proportional to the amount of charge concentrated virtually at a point; it is inversely proportional to the square of the distance radially away from the source charge’s centre and relies on the nature of the medium. The electric field is reduced below its value in a vacuum when a material medium is present.

Test Charge

Introducing a small test charge with its electric field somewhat changes the present field. The force per unit of the positive ions applied before the presence of the test charge causes the field to be disturbed; this is considered the electrical field.

Properties of Electric Field Lines

• The field lines never cross one another.
• The field lines run perpendicular to the charge’s surface.
• Both the amount of the charge and the number of field lines are proportional.
• The field lines begin with the positive charge and conclude with the negative charge.
• A single charge must be used to start or finish the field lines at infinity.

The Direction of Electric Field

The force on a negative ion is the polar opposite of the force on a positive ion. Because an electrostatic force has both size and direction, the path of the force on a positive charge is selected at random as the applied field direction. As the positive charges repel one another, the electric field in an independent positive charge is oriented outward. When depicted by line segments of force or field lines, electric fields are shown to originate on positive charges and terminate on the negative charges.

Source of Electric Field

The electric field, accompanied by a magnetic field, travels through space at the speed of light as a radiated wave. According to such electromagnetic waves, electric fields are formed by electric charges and by changing magnetic fields. As in the case of charges accelerating up and down the transmitting antenna of a television station, the electric field can get disconnected from the source charge and form closed loops.

Electric Field Due to Point Charge

Coulomb’s law calculates the electric field of a point charge:

E= F/Q = KQq/qr2

E = KQ/r2

From the point charge, the electric field expands outward in all directions. Circles show spherical equipotential surfaces.

The electric field may be calculated using a summation of the specific fields from any number of point charges. An outward field is related to a positive number, whereas an inside field is associated with a negative charge.

Relation with Magnetic Field

Electrodynamics is the study of time-varying magnetic and electric fields. Faraday’s law describes the link between a time-varying magnetic field and the electric field. According to Faraday’s law, the curl of the electric field is equal to the negative time derivative of the magnetic field. The electric field is consequently considered conservative without a time-varying magnetic field (i.e. curl-free), suggesting two electric fields -electrostatic and magnetic fields – that change over time. While the curl-free character of the static electric field makes electrostatic treatment easier, time-varying magnetic fields are usually a component of a unified electromagnetic field.

Conclusion

An electric field is a force per unit charge; it is a scalar quantity. The strength of an electric field is predicted by the position of electric field lines – whether they are proximal or at a distance. Electric field due to point charge inversely depends upon the square of the distance and directly depends upon the source charge. Faraday described the relationship between the electric and magnetic fields. A charge at rest can produce an electric field; a moving charge can create both electric and magnetic fields.