Electromagnetic Induction

Subject: 

PHYSICS

[mediator_tech]

Term:

FIRST TERM

Week:

WEEK 4

Class:

SS 3

Topic:

Electromagnetic Induction

Michael Faraday in 1832, at the age of 41 discovered that electricity could be produced without any battery by using magnetic fields. This phenomenon is called “Electromagnetic when the speed of the relative motion Induction”.

“Electromagnetic induction is thus defined as a process whereby an emf is produced or induced in a conductor by the relative motion of the conductor and a magnetic field”. Experiments show that:

1. an emf is induced in the coil whenever there is a relative motion between the coil and the
2. the magnitude of the induced emf increases when the speed of the relative motion between the magnet and the coil, the strength of the magnet, the number of turns of the coil all increases.
3. the induced emf would also increase if there is soft iron core inside the coil.

Electromagnetic induction is a fascinating phenomenon that has played a major role in the development of modern society. Thanks to this discovery, we are able to produce electricity and use it to power our homes, businesses, and devices. There are many practical applications of electromagnetic induction as well, including generators, electric motors, transformers, and magnetic resonance imaging (MRI) machines. Despite all of the incredible advances that have been made as a result of electromagnetic induction, there is still much to learn about this fascinating phenomenon and how we can continue to harness its power in new and exciting ways.

However, current can also be induced in a straight conductor when a magnetic field is applied perpendicular to it. The direction of the current is given by FLEMING’S RIGHT HAND RULE, which state that, ‘’If the first three fingers of the right hand are held at right angle to each other, with the Forefinger in the direction of the field, and the thumb in the direction of the motion, then the middle finger is in the direction of the induced current’’.

Note that FLEMING’S LEFT HAND RULE is used to determine the direction of current in a conductor; while FLEMING’S RIGHT HAND RULE is used to determine the induced emf in a magnetic field.

Overall, electromagnetic induction is one of the most important discoveries in the history of science, and its applications continue to have a major impact on our society today. Whether we are powering our homes or using MRI machines to diagnose medical conditions, we can all be thankful for the contributions made by Michael Faraday and other scientists who have studied this fascinating phenomenon.

The Laws of Electromagnetic Induction

There are three main laws of electromagnetic induction that govern the behavior of this phenomenon:

1. The first law states that when a conductor is moved in a magnetic field, an electromotive force (emf) is produced in the conductor. This is known as Faraday’s law of induction.

2. The second law states that the magnitude of this emf is directly proportional to the rate of change in magnetic flux. This is also known as Lenz’s law.

3. The third law states that if a conductor cuts across a magnetic field, an emf will be induced in that conductor in such a direction that it opposes the motion across the field and creates a magnetic field that acts to maintain the current.

While these laws provide important insights into the behavior of electromagnetic induction, there is still much that we do not understand about this phenomenon and how it can be used in a variety of applications. Despite this, scientists continue to study electromagnetic induction and look for ways to harness its power for new advances in fields such as energy generation, medicine, and technology. Ultimately, the study of electromagnetic induction represents an essential aspect of modern science and one that will continue to play an important role in shaping our world for years to come.

Eddy Currents

and Electromagnetic Induction

One important phenomenon related to electromagnetic induction is eddy currents. These currents are induced in conductive materials when they move through a changing magnetic field, and can have an impact on the behavior of various systems. For example, eddy currents can affect the temperature, strength, or magnetic permeability of certain materials, thereby affecting their overall performance.

Eddy currents are also widely used in devices such as generators and transformers, where they can be harnessed to generate or transmit power. In addition, studies have shown that eddy currents may play an important role in the development of new technologies for magnetic resonance imaging (MRI), which has become a critical tool in modern medicine.

Overall, eddy currents are a fascinating phenomenon that can have significant impacts on our world, and scientists continue to explore their underlying mechanisms and applications. By gaining a better understanding of these currents, we may be able to unlock new insights into the use of electromagnetic induction for energy generation and other important technologies.

Advantages and Disadvantages of Eddy Currents

1. One major advantage of eddy currents is that they can help to generate or transmit power in a variety of systems. This makes them useful for applications such as electrical generators, where they can be used to convert mechanical energy into electrical energy.

2. In addition, eddy currents may play an important role in the development of new technologies for magnetic resonance imaging (MRI). These currents allow researchers to observe minute changes in the magnetic properties of materials, which has made MRI a powerful tool for diagnosing medical conditions.

3. Another major advantage of eddy currents is that they can be used to increase the strength and performance of certain conductive materials. For example, these currents can help to increase the magnetic permeability of certain metals, which makes them stronger and more useful for applications like electrical circuit wiring.

4. A potential disadvantage of eddy currents is that they may have negative impacts on the overall performance of certain materials. This is because these currents can cause a buildup of heat in conductive parts, which may affect the strength or durability of the materials.

5. In addition, eddy currents may sometimes create unwanted electrical noise that can interfere with other devices. For example, these currents may cause interference with communication signals or electrical equipment if they are not properly controlled and managed.

Disadvantages of Eddy Currents

The disadvantages of Eddy currents include the following:

• They generate heat in materials;
• The heat generated leads to wastage of energy in electrical devices.

EVALUATION

1. Define an electromagnetic induction.
2. State the laws of electromagnetic induction.
3. What is eddy current?

GENERAL EVALUATION

1. Highlight the applications of the electromagnetic field.
2. Discuss the magnetic field around two parallel current-carrying conductors whose current’s direction is the same.
3. Itemise the demerits of the eddy current.
4. What is electromagnetic induction?