Difference between Electric Field and Magnetic Field

Difference between an Electric Field and a Magnetic Field is Electric Field is the region around an electric charge in which another charge experiences the force of attraction and repulsion, whereas a magnetic field is the region around magnetic material in which it attracts or repels other magnetic materials.

Before learning the difference between an electric field and a magnetic field, let’s learn about what is electric field and what is magnetic field, their difference, and others in detail.

What is a Magnetic Field?

The region around the magnetic material where its poles exhibit a force of attraction or repulsion is called a magnetic field. The magnetic field is also induced when the electric charges are moving in space or an electrical conductor. The magnetic field is a vector field present around magnets, moving electric charges, and changing electric fields.

Magnetic Field Formula

Magnetic field formula has constant μ₀ known as the permeability of free space. Magnetic field is represented by the symbol ‘B’ and the unit of magnetic field is Tesla (T). Magnetic field lines are imaginary lines used to describe the direction of the magnetic force. The formula for magnetic field strength is given below:

Magnetic force (B) = μ₀I/2πr

where,

• B is magnitude of Magnetic field in Tesla (T)
• μ₀ is permeability of free space (4π × 10⁻⁷T⋅m/A)
• I is the magnitude of the electric current in amperes (A)
• r is the distance in meters (m)

A magnetic field is produced when current is passed through a magnetic material. The needle will deflect if a needle is placed near the material to provide the electric charge (moving charges). The area to the point where the magnetic material exerts the force is called a magnetic field and is the result of magnetism.

Magnetic Field Line

Magnetic field lines are imaginary lines used to represent magnetic field, and a tangent to it depicts the direction of the magnetic force. The moving charges and magnets produce the magnetic field lines. Some important properties of magnetic field lines are as follows,

• Two magnetic field lines never intersect each other.
• Magnetic field lines are continuous closed loops.
• They are directed from the north pole to the south pole of the magnet (outside the magnet) and directed from the south pole to the north pole of the magnet (inside the magnet).
• The tangent at any point on the magnetic field lines gives the direction of the magnetic force at that point.
• The closer the magnetic field lines, the stronger will be the magnetic force and vice-versa.
• Magnetic field lines are crowded near the poles and less dense when away from the poles.

The image of Magnetic Field Lines by a bar magnet is shown in the image below,

Example: Find the magnitude of the magnetic field that is 0.10 m away from a wire carrying a 3.00 A current. Also, if the current has a vector direction out of the page (or screen), then what is the direction of the magnetic field?

Given,

• r = 0.10 m
• I = 3.00 A

By using the formula we can calculate the magnetic field,

B = μ₀I/2πr

Substituting the values, 

B = (4π × 10⁻⁷ T⋅m/A)(3.00 A)2π(0.10 m)

B = (4π × 10⁻⁷ T⋅m/A)(3.00 A)2π(0.10 m)

B = (4π × 10⁻⁷)(3.00)2π(0.10) T

B = (4π × 10⁻⁷)(3.00)2π(0.10) T

B = 4π(3.00)2π(0.10) × 10⁻⁷ T

B = 2(30.0) × 10⁻⁷ T

B = 60.0 × 10⁻⁷ T

B = 6.0 ×10⁻⁶ T [Since 10^-6 T = 1 μT]

B = 6.0 μT

What is Electric Field?

The force around the unit electrical charge particle is called an electrical field or electric field intensity. In other words, it is an area around the electric charge where another electric charge experiences the electric force. Electric field is a vector quantity, so it has both magnitude and direction. The symbol  expresses the electric field, and it is measured in newton/coulomb.

Electric Field Formula

The formula for electric field can be given as,

=

where,

• is the electric force in Newton (N)
• q is charge in Coulomb (C)

Example: A force of 2 N is acting on the charge 6 μ C at any point. Determine the electric field intensity at that point.

Given,

• Force F = 2 N
• Charge q = 6 μC = 6 × 10^-6 C

Electric field intensity formula is given by,

E = F / q

E= 2 N/6 × 10^-6 C = 3.34 ×10⁵ N/C

Thus, the electric field intensity is 3.34 ×10⁵ N/C

Electric Field and Magnetic Field   

Electric field and magnetic field are correlated with each other. Electric field can be generated with a varying magnetic field and a magnetic field can be generated with a varying electric field. A moving charge or electric current will have both electric and magnetic fields together, they create electromagnetic field and cause electromagnetic induction. Let’s take a look at the major differences between electric field and magnetic field:

Electric Field Vs Magnetic Field
Electric Field	Magnetic Field
Electric field is a region where a force is experienced by the electrical charge.	The magnetic field is a region around the magnetic poles where an attraction or repulsion is experienced by the magnetic material.
The S.I. unit of the electric field is Volt/meter or Newton/Coulomb	The S.I. unit of the magnetic field is Tesla, or (Newton × Second)/(Coulomb × Meter)
The symbol of the electric field is \overrightarrow{E}	The symbol for magnetic field is \overrightarrow{B}
Electric field is perpendicular to the magnetic field.	Magnetic field is perpendicular to the electric field.
Originates on a positive charge and terminates on a negative charge.	It originated at the North Pole and terminates at the South Pole.
Electric field lines do not form a closed loop.	The magnetic field lines form a closed loop.
It has a negative and positive charge.	It has a north and south Pole.
Repulsion force on like charges and attraction force on unlike charges.	Repulsion force on like poles and attraction force on unlike poles.
The electric field can do work (the speed and direction of particles change).	The magnetic field cannot do work (Force is always perpendicular to the velocity of the moving charge).

Read More,

• Gauss’s Law
• Coulombs Law

Electric Field and Magnetic Field-FAQs

1. What is Relation Between Electric Field and Magnetic Field?

A static charge has electric field, and when the charge is dynamic, it has both electric and magnetic fields. Here, both fields are perpendicular to each other, and together they are called the electromagnetic field.

2. What is the Unit of Electric Field?

The unit of electric field is Newton/Coulomb or Volt/Meter.

3. What is the Unit of Magnetic Field?

The unit of magnetic field is measured in Tesla or Gauss.

4. What are Similarities between Electric Field and Magnetic Field?

There is a certain analogy that can be observed between electric field and magnetic field. Electric field is produced by positive and negative charges. Similarly, the magnetic field is produced by north and south poles. Similar charges and similar poles repel each other, opposite charges and opposite poles attract each other.

5. What is Phase Difference between Electric Field and Magnetic Field?

The time phase difference between electric field and magnetic field is 0°.