Electric motor and Electromagnetic Induction

Electric Motors

The electric motors are machines that run on electricity and help with the conversion of the electrical energy into mechanical energy. The motors are installed in a range of appliances and industrial machines which are designed for continuous rotation or linear movement. The interaction between the motor’s magnetic field and electric current helps in generation of force in the form of torque which helps in operation of the machine. The Fleming’s left-hand rule is used to determine the direction of motion of the electric motor and direction of the motor’s motion.

Electromagnetic Induction: 

It is the phenomenon of the production of induced current in a coil placed in a region where the magnetic field changes with time.

• The magnetic field may change due to a relative motion between the coil and a magnet placed near the coil.
• If the coil is placed near a current-carrying conductor, the magnetic field may change either due to a change in the current through the conductor or the relative motion between the coil and conductor.
• Fleming’s right-hand rule gives the direction of the induced current.

Faraday’s first law of electromagnetic induction :

For the purpose of deriving the laws of electromagnetic induction Michael Faraday performed many experiments. His three experiments amongst all are the most important ones in the discovery of electromagnetic induction. 

Michael Faraday has given two laws of electromagnetic induction.

In his first law of electromagnetic induction, for the purpose of understanding electromagnetic induction in detail Faraday and Henry worked together. Experiment by Faraday concluded that the electromotive force is generated in the coil when there is a change in the magnetic flux across the coil with time. It is the first conclusion made by Faraday after his many experiments. Thus, we can estate the first law of Faraday regarding the electromagnetic induction as following:

An electromotive force (emf ) is generated when a current is induced in a conductor circuit which creates a variation in the magnetic field.

The current which is induced in a circuit is termed as induced current when the conductor circuit is closed. 

We can bring change in the magnetic field intensity in a closed loop via different ways. Let us discuss some of them below :

• A change in the magnetic flux can be brought by rotating the coil which is relative to the magnet.
• A change in the magnetic flux can also be brought by moving the coil into the magnetic field.
• Bringing the coil out of the magnetic field can also bring a change in the magnetic flux.
• We can also change the area of the coil which is placed in the magnetic field.
• We can move the magnet towards the coil to bring a change in the magnetic flux.
• Moving the magnet away from the coil can also bring change in the magnetic flux.

Faraday’s second law of electromagnetic induction:

According to Faraday’s second law of electromagnetic induction the emf or electromotive force generated by the change in the magnetic field in the coil is equal to the rate of the change of the flux leakage.

The flux is referred to the product of the number of the turns of wire in the coil, the flux associated with the coil.

Methods to increase the induced electromotive force in a coil:

• If we increase the number of the turns in a coil the induced electromotive force will increase.
• If we increase the strength of the magnetic field the electromotive force will increase.
• If we increase the speed of relative motion between the coil and the magnet the electromotive force will increase.

Magnetism in Medicine: 

• An electric current consistently delivers a magnetic field. Indeed, even feeble ion currents that move along the nerve cells in our body produce magnetic fields.
• Our nerves carry an electric impulse to the muscles, and this impulse produces a temporary magnetic field.
• The magnetic field inside the body forms the basis for obtaining different body parts’ images. Analysis of these images helps in medical diagnosis.
• This technique is called Magnetic Resonance Imaging (MRI).  

Electric Generator:  It is a device that converts mechanical energy into electrical energy. It works on the principle of electromagnetic induction.  

Domestic electric circuits:

• AC electric power of 220 V with a frequency of 50 Hz is received in domestic supply.
• One of the wires in this stockpile is with red protection, called live wire. The other one is of dark protection, which is a nonpartisan wire. The likely distinction between the two is 220 V.
• The third is the earth wire with green insulation, associated with a metallic body somewhere inside the earth. It is used as a prosperity measure to ensure that any spillage of current ​to a metallic body doesn’t give any genuine shock to a user.
• Fuse is the main wellbeing gadget utilized for securing the circuits because of short-circuiting or over-burdening of the circuits.

Conclusion :

The term electromagnetic induction refers to the production of electric currents which are caused by the magnetic field. A magnetic field produces current in a conductor. His law is related to the production of electromotive force. Faraday’s law of induction is the basic operating principle of inductions, electric generators, electric motors, power transformers, musical instruments such as electric guitar, electric violins etc. Science class 10: Electric motor and Electromagnetic Induction is an important topic which helps in understanding concepts of electric motor, electromagnetic induction, and the laws explaining the concept.