Electromagnetism

Electromagnetism

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Electromagnetically, the electric force between electrically charged particles is a physical field that deals with the electromagnetic force.

The electromagnetic force is one of the major four forces including electromagnetic fields namely magnet fields, electrical fields, and light.

That is the underlying explanation of why electrons are attached to the nucleus and responsible for the whole nucleus structure.

What is Electromagnetic Force?

The electromagnetic force is a form of physical interaction between particles charged with electricity. It operates amongst charged particles and integrates both magnetic forces with electrical forces.

It may be desirable or abusively electromagnetic.

Before the discovery of electromagnetism, electricity and magnetism were historically considered by persons or physicists. James Clerk Maxwell wrote the Electricity and Magnetism Treatise in 1873.

The view has shifted. The publication notes that one power mediates the relationship between positive and negative charges.

The basis for this discovery was Electromagnetism. Many physicists, such as Michael Faraday, Oliver Heaviside and Heinrich Hertz, then made their contribution to electromagnetics.

 

What is Electromagnetism?

What is Electromagnetism

Electromagnetism is a method of placing the current in the conductor, producing a magnetic field. When a driver is charged electrically, magnetic conductive force lines are generated.

thumb motion

For example, if current i.e. positive fees pass in a wire, the magnetic field can be generated along a wire and the magnetic line directions and force can be described using the law of the right hand.

For a detailed explanation, see the picture below.

 

Read also: Temperature

 

Explanation of Electromagnetism with an Example

Explanation of Electromagnetism with an Example

Permanent Magnetic speakers commonly used in TV’s and Radios are perfect examples of Electromagnetic devices.

Let’s see the operation of these devices which are based on the principle of electromagnetism.

Also Checkout:  Turning Effect of Force

See the picture below.

In order to convert electrical waves into an audible sound, the speakers are designed. A metal coil is attached to a permanent magnet and when current passes through the coil it generates a magnetic field.

The newly formed magnetic field is repelled by the permanent magnetic field resulting in the vibrations. These vibrations are amplified by the cone-like structure causing the sound. This is how speakers work based on electromagnetism.

Electromagnetic Induction

We have seen what happens when a conductor is electrically charged. Now, let’s see what happens if we place a conductor in between the magnetic field.

When a conductor is placed or moved through the magnetic field it generates voltage i.e., electricity. This principle is called Electromagnetic Induction.

The voltages generated will be based on the speed of the conductor moving through the electric field. Faster the speed of the conductor, the greater the induced electricity or voltage.

 

Faraday’s Law

According to  Faraday’s Law, the relative motion between magnetic field and conductor, the flux linkage changes and this change in flux induces a voltage across the coil.

 

Explanation with an example

Faraday’s Law

DC Generator works on the principle of Faraday’s Law of Electromagnetic Induction. It is a system that converts mechanical energy into electrical energy.

In the above figure, A rectangular conductor width sides are placed in between a magnetic field. When the rectangular conductor rotates in between magnetics, it cuts the magnetic field thereby causing the Electromagnetic field (e m f).

 

A few properties of electromagnetic waves are:

  • Electromagnetic waves are propagated by oscillating waves electric and magnetic waves oscillating at right angles to each other
  • They exhibit the properties of interference and diffraction
  • They travel at a speed of 3 × 108 m/s in a vacuum.
  • They are transverse waves.
  • The relationship between the wavelength (λ) and frequency (c) of an electromagnetic wave is given as follows:
Also Checkout:  Sound

c = v λ

A few applications of electromagnetism are:

  • For many domestic’s equipments in home applications, electromagnetism is an integrated operating concept.
  • The concept of the electromagnetic is used for the Maglev trains or high-speed trains.
  • The transmission device uses electromagnetic radiation to move data from the source to the recipient
  • Electromagnetism is used at least at one point in the industry from small devices to large-scale electrical equipment.

 

Read also: Sound

 

Force on a moving charge in a magnetic field:

Force on a moving charge in magnetic field

Now if we consider a charge entering a magnetic field with direction into the plane, the direction of current will be the convectional current direction i.e. from positive to negative (the direction of current is shown).

Now if you apply left hand rule, you’ll get the direction of the force it will experience, which will be upwards.

 

Forces between two parallel current-carrying conductors:

Forces between two parallel current-carrying conductors

If two parallel wires are placed together, we know they will generate a magnetic field around them, right? The wires will experience a force. Why? Let’s see!

If you right-hand rule on the current-carrying wires, you’ll get the direction of the fields around them. Now if the direction of the current in both wires is the same, they will attract.

If, however, the direction is opposite, they will repel. This is because the field direction in the wires with the same current direction will be the same. See the diagram carefully and draw it yourself, you’ll understand how this happens.

 

Force on the current-carrying rectangular coil in a Magnetic field:

Force on current-carrying rectangular coil in a Magnetic field

If a current-carrying coil is placed in a magnetic field (As shown in diagram above), a pair of forces will be produced on the coil. This is due to the interaction of the magnetic field of the permanent magnet and the magnetic field of the current-carrying coil.

Also Checkout:  Current Electricity

The direction of the force can be determined by Fleming’s left-hand rule. Since the current in both sides of the coil flow in opposite direction, the forces produced are also in opposite direction. The 2 forces in opposite direction constitute a couple which produces a turning effect to make the coil rotate.

norh south

This phenomenon is used in a d.c. (direct current) motor. What does an electric motor do? It simple converts electric energy to kinetic energy. The d.c. the motor consists a rectangular coil of wire placed between 2 permanent magnets.

The coil are soldered to a copper split ring known as a commutator. 2 carbon brushes are held against the commutator.

 

This is shown below:

direct current motor

The function of the brush is to conduct electricity from the external circuit to the coil and allow the commutator to rotate continuously (since the brush is of carbon, it conducts electricity).

The function of the commutator is to change the direction of the current in the coil and hence change the direction of the couple (the 2 forces in opposite direction) in every half revolution. This is to make sure that the coil can rotate continuously.

 

 

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