Difference Between Electromagnet and Permanent Magnet

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Electromagnets are soft iron cores that are made into magnets on passing an electric current through the coil surrounding them. 

A permanent magnet is something that is an innate ability of a magnet that continues to show magnetism even if it is removed from the magnetic field

So, here if we differentiate between an electromagnet and a permanent magnet, it seems that permanent magnets are better than electromagnets; however, each of these has its own advantages. 

This article discusses the difference between an electromagnet and a permanent magnet in points.


Electromagnetism Meaning 

The word ‘Electro’ in electromagnetism talks about the magnetism that is caused by the effect of electricity, and soon it loses its magnetism when it is brought away from the area of the magnetic field.


Permanent Magnetism Meaning

The word permanent talks about something that remains firm or permanent. Here, permanent magnetism means a magnet that retains its magnetism after removal of the magnetizing force or after taking a magnet from the vicinity of the magnetic field. 

The below diagram represents the difference between the electromagnet and permanent magnet:

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Differentiate Between Permanent Magnet and Electromagnet

Parameters

Permanent Magnetism

Electromagnetism

Definition

A permanent magnet is an object made of a material that gets magnetized and creates its own persistent magnetic field. 

An electromagnet is made from a coil of wire that acts as a magnet when an electric current is allowed to pass through it.  

Meaning

As the name ‘permanent magnet’ suggests, it always has a magnetic field and displays its magnetic behaviour forever.

As the name suggests ‘electromagnet’ means temporary. 

It works like a magnet as long as the current passes through the coil. 

Made of 

A permanent magnet is made of hard materials like steel.

It is made of a soft iron core.

Magnetism

It generates the magnetic field by itself and that remains persistent forever. 

The electromagnet is often wrapped around a core of the ferromagnetic material like steel that increases the magnetic field generated by the coil. 

The need for an electric current supply

Permanent magnets do not need an electric current to behave as a magnet.

Electromagnets require an electric current to work as a magnet.


Now, let’s discuss more on to distinguish between the electromagnet and permanent magnet:


Parameter

Electromagnet

Permanent Magnet

Magnetic field strength

The magnetic field strength of electromagnets can be changed/altered. 

As the name suggests ‘permanent’, its magnetic field strength remains like its name.

Nature of magnetic field

Temporary

Permanent

Strength of magnetic field

The magnetic field of electromagnets can be very strong. 

The nature of magnetism or the magnetic field is weaker as compared to electromagnets.

Changing the magnetic field

The magnetic field of electromagnets can be altered by controlling the flow of the electric current.

The magnetic field of permanent magnets cannot be changed, as it remains constant.

Magnetic force

Electromagnets are temporary, as these magnets work on magnetic forces only when an electric current passes through them. 

Permanent magnets generate a weaker magnetic force as compared to electromagnets.

Polarity

The polarity of an electromagnet can be reversed.

We can not reverse the polarity of permanent magnets.

Demagnetizing

Electromagnets can be easily demagnetized by switching off the current.

We cannot demagnetize the permanent magnet.

Example

An example of an electromagnet is a solenoid wrapped with a wire or a coil and connected to the battery.

A bar magnet is an example of permanent magnets.

Usage

Used in devices like electric fans

Electric motors:


There are a total of three permanent magnets in the electric motor

First: powering the front axle 

Second and third: A pair at the rear, each driving its own wheel.

Applications

Electric fans, electric bell, telegraph, debit cards, credit cards, etc.

Electric clocks, microphones, speakers,  electrical devices like generators, motors, scientific instruments, etc.


Difference between Permanent and Electromagnet

Now, let’s discuss more to differentiate between the electromagnet and permanent magnet:

The table below lists the difference between the electromagnet and permanent magnet:


Parameter

Permanent magnet

Electromagnet

Retaining of magnetic property

Permanent magnets can retain their magnetic property for a long period until it gets demagnetized because of various factors.

Since electromagnet is a temporary magnetic, so its magnetic effect can be utilized by switching on the current when needed.

The magnitude of magnetic field strength

The magnitude of the magnetic field can be increased or decreased by changing the magnitude of the current supply.

The magnitude of the magnetic field cannot be increased or decreased by changing the magnitude of the current supply, as it remains the same forever.

Mode of study

Electromagnetism deals with both electricity and magnetism and the interaction between them.

Permanent magnetism or magnetism is the force that can cause two objects to attract or repel each other because of the motion of moving charges. 

Phenomenon

Electromagnetism deals with both electric and magnetic fields.

Magnetism deals with magnetic fields or magnetic forces.

FAQ (Frequently Asked Questions)

Question 1: How Electromagnets Differ from Permanent Magnets?

Answer: We know that permanent magnets are made of hard materials, which are ferromagnetic in nature, and they are also referred to as electromagnets with a continuous current flowing thereby making each and every atom inside the wire, a magnet.

If we talk about electromagnets, their magnetism disappears with the passage of time.

The key difference between an electromagnet and a permanent magnet is that the electromagnet can have a magnetic field when an electric current flows through it and disappears when the flow of the current stops, while permanent magnets are made up of magnetic material that can be easily magnetized and can create its own magnetic field.

Question 2: What is the Theory of Electromagnetism?

Answer: A theory of electromagnetism is also known as classical electromagnetism. It was developed by various physicists during the period between 1820 and 1873 when it was in the publication of a treatise by James Clerk Maxwell, where he unified the ongoing developments into a single theory and discovered/founded the electromagnetic nature of light.

This theory covers the basic principles of the following things:

  • Principles of electromagnetism: its experimental basis

  • Electrostatics

  • Magnetic fields of steady currents

  • Motional e.m.f. and electromagnetic induction or EMI

  • Maxwell's equations

  • The propagation and radiation of electromagnetic waves or EMW, 

  • Electric and magnetic properties of matter, and c

  • Laws of conservation