[Physics Class Notes] on Displacement Current Pdf for Exam

The rate of change of the electric displacement field is known as the displacement current. It is calculated in the same way as electric current density is calculated.

Maxwell’s Equation includes a term called displacement current. It was created to bring the Ampere circuit law into line with logic. Ampere (Amp) is the SI unit for displacement current.

This dimension can be measured in length units, which can be maximum, minimum, or equivalent to the actual distance traveled from start to finish.

Displacement current is an electric current created by a time-varying electric field rather than by moving charges.

Characteristics of Displacement Current

• Displacement current is another type of current apart from conduction current.

• As with conduction current, it does not appear from the actual movement of electric charge.

• It is a vector quantity.

• It is vital for electromagnetic wave propagation.

Maxwell’s Equation is a good way to explain displacement current.

Maxwell-Ampere Law and Equation

Electricity and magnetism are important aspects of physics. Because electricity and magnetism are intrinsically related, they are grouped as electromagnetism.

A current-carrying wire provides insight into electromagnetism. When an electric current flows via a wire, it creates a magnetic field around the wire or conductor.

This current, which travels through a conductor, is known as the conduction current. It is caused by electrons moving through a conductor. 

Since we learned about displacement current earlier, it is now important to note that displacement current is distinct from conduction current. Because displacement current does not carry electrons.

Now let’s understand the relationship between displacement and Maxwell Ampere law.

1. Ampere’s law was developed by Andre-Marie Ampere. It states that :

Here Maxwell gave an addition to Ampere’s law which resulted in Maxwell-Ampere Law.

2. James Clerk Maxwell, a famous physicist, well known for his work on Maxwell’s equations gave addition to Ampère’s law which stated that:

Equation of Maxwell-Ampere Law

Maxwell predicted that a time-varying electric field in a vacuum/free space (or in a dielectric) produces a magnetic field.

It indicates that a changing electric field causes a current to flow across a region. Maxwell also predicted that this current produces a magnetic field similar to that of a conducting current. “Displacement current” (ID) was the name given to this current.

The equation is:

[I_{D}=epsilon _{o}frac{dphi E}{dt}]

Where [phi E] is the Electric Flux

Maxwell also stated that when conduction current (I) and displacement current (ID), are combined, they have the property of continuity, even though they are not continuous individually.

Maxell was inspired by this idea and modified Ampere’s circuital law to make it logically consistent. Thereafter he stated revised Ampere circuital law which now is known as Ampere-Maxwell law.

From

[oint _{C}vec{B}.vec{dl}=mu _{o}(I+I_{D})]

[mu _{o}(I+epsilon _{o}frac{dphi E}{dt})]