Difference between Electric Field and Magnetic Field

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What is the Difference between Electric Field & Magnetic Field?

The electric field and magnetic field are both fundamentals of electrical and electronics engineering. The electric field is the area surrounding a charged particle while the magnetic field is the area surrounding a magnet. A moving charge produces both an electric & magnetic field known as electromagnetic field. These two fields are somewhat related but they are not dependent on each other. Other than that there are many differences between electric field & magnetic field.

Before going into the differences between electric field & magnetic field, we are going to discuss their basics first.

Table of Contents

Electric Field

The electric field is defined as “the area around a charge in which the effect of that charge can be felt, is known as the electric field.” The electric field exerts force on other charges.

A charge can exert force on other charges in its electric field either attracting or repelling them. The path along which a tiny positive charge moves in an electric field is known as electric field lines.

It is denoted by ‘E’. It is measured in newton per coulomb equivalent to volt per meter. The instrument used for measuring the electric field is known as Electrometer. Whereas the strength of the field cannot be determined on its own but it takes another charge to measure it.

An electric field is either generated surrounding an electric charge (positive or negative) or by varying a magnetic field with respect to time.

The electric field is visualized by lines of force or field lines. They represent the path a unit positive charge would follow inside an electric field. The electric field line generated by a stationary charge originates from a positive charge and terminates at negative charge. Therefore, a stationary positive charge has electric field lines pointing outwards while a stationary negative charge has electric field lines pointing inwards. While the electric field between two positive & negative charge originates from a positive charge & terminates on a negative charge.

Therefore, two same charges will repel each other as their electric field lines will repel each other. While two opposite charges attract each other as their electric field lines attract each other.

The electric field intensity is the electric field lines per unit area. It varies with the amount of charge & decreases with the square of the distance from the source charge. The force acting on an electric charge inside an electric field depends on the amount of charges & the distance between them.

A moving charge does not only have electric field but also produces magnetic field where both of them are mutually perpendicular. Therefore, the electric field & magnetic field are associated with each other. However, they can exist on its own & one does not depend on the other. It results in another term known as electromagnet. Electromagnetism has a wide range of application used in our daily life.

Electric Field Equation:

Force per unit charge is known as electric field intensity.

E = F ÷ Q

Where:

E = Electric Field Intensity
F = Force
Q = Electric Charge

The electric filed strength in volt per meter formula is as follow:

ε = e ÷ d

Magnetic Field

A magnetic field is an area surrounding a magnet in which the effect of that magnet can be felt. The poles of other magnets experience a force of attraction or repulsion inside a magnetic field.

A magnetic field is generated by a source magnet or by a time-varying electric field.

A magnetic field is donated by ‘B’ & its unit of measurement is Tesla (T) or Gauss (G). The instrument used for the measurement of the magnetic field is called magnetometer.

A magnetic field can be generated either by a magnet or a time-varying electric field.

A magnet poses two poles called north & south poles. The magnetic field line originates from the north pole & goes into the south pole of the magnet. The magnetic field lines go into the south pole forming a closed loop. Whereas the electric field lines do not form a closed loop.

Therefore, the Magnetic field only exists in a dipole i.e. it always has two poles north & south poles joined by a closed loop of magnetic field lines. While electric can exist in monopole forming straight lines going outward or inward in a charge.

Related Post: Difference between Electron Current and Conventional Current

Magnetic Field Equation:

B = Φ_b ÷ A

Where:

B = Magnetic field
Φ_b = magnetic flux
A = area

Differences between Electric Field & Magnetic Field

The following comparison table shows the main differences between magnetic field and electric field.

Electric Field	Magnetic Field
The area surrounding an electric charge where its effect is felt.	The area surrounding a magnet where its effect is felt.
It exerts a force of repulsion or attraction on other charges.	It exerts a force of repulsion or attraction on poles of other magnets.
It is denoted by the symbol “E”.	It is denoted by the symbol “B”.
Its formula is E = F / Q.	Its formula is B = Φ_b / A.
Its unit of measurement is newton / coulomb (N/C) or volt / meter.	Its unit of measurement is Tesla (T) or Gauss (G), where 1 Tesla = 10,000 Gauss.
It is measured using an electrometer.	It is measured using a magnetometer.
It is inherently generated surrounding a charge or by varying a magnetic field.	It is generated surrounding a magnet or by varying an electric field.
Electric charges can be either negative or positive both having electric fields on its own.	The magnet always has two poles i.e. north pole & south pole.
Electric field lines originate from positive charge & terminate at a negative charge.	Magnetic field lines originate from the north pole & goes into the south pole.
The electric field lines does not form closed loop.	The magnetic field lines form closed loop.
It is mono pole i.e. single separate charge having straight electric field lines outward or inward.	It is dipole i.e. every magnet has north & south pole & magnet field lines start from north pole into the south pole.
In electromagnetic wave, it oscillates perpendicular to the magnetic field.	In Electromagnetic wave, it is perpendicular to the electric field.
It exists in two dimensions.	It exists in three dimensions.
Electric field can do work i.e. the particles change direction & moves.	It cannot do work i.e. the particles change direction but does not move.

Difference between Electric Field and Magnetic Field