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Chapter 7

Electricity & Magnetism

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The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

Introduction

You must wonder sometimes how electrical appliances work and how light is generated. Electricity and magnetism are one of the most interesting subjects in physics. We will talk about magnetism and electricity and the interaction that exists between them. We will also learn interesting topics related to them, such as the electricity test for a magnet, electron motion, conductors, semiconductor and insulators, magnetic fields, etc.

Electricity is the existence and movement of the charged particles. How does electricity flow through copper wire and space? What is the electrical current, the electromotive power, and what makes the landing light turn on or the hydraulic pump engine run? All of these issues include an awareness of a number of fundamental concepts. By applying one simple concept to the other basic ideas, most of the important and realistic questions concerning electricity or electronics can be answered. Our interpretation of electrical current must begin with the essence of the matter. Everything matter is made up of molecules. Both molecules are made up of ions, made up of electrons, protons, and neutrons.

How does magnetic effect work?

Let’s start with an exercise, you can do this at home with materials you can find around you. You will need:

    • A battery cell
    • Insulated wire 10cm long
    • Electrical tape
    • A good neodymium magnet
    • Pen and paper to note your observation
  1. Get the insulated wire, strip off the insulation for around 1 cm on either side.
  2. Connect one end of the wire to the positive terminal of the battery and, if possible, use the electrical tape.
  3. Place a good neodymium magnet under the wire, do not connect the wire and take note of your findings.
  4. Now link the free end of the wire to the negative terminal and see what happens.
  5. Now leave the wire where it is and adjust the terminals of the battery. Note down your observations.

Inference:  It is observed that the wire bends as the current flows through it, and when the polarities are reversed, the wire bends in the same direction.

Each part and product of the electrical circuit includes a symbol. The symbols represent the circuit parts in the circuit diagram. Below are the fundamental set of symbols used in the circuit diagram.

 

  • Electric cell (dry cell): The electrical cell, also known as a dry cell, is the main component of the electrical circuit. This provides our electrical energy tools and devices for working. The cells have both a positive and a negative terminal. This is represented in the electrical circuit as two parallel lines of unequal length. The longer line is the positive end and the shorter line is the negative terminal. In simple words, a battery is a collection of cells put together.
  • Electric bulb: The electrical bulb is a component of the electrical circuit that works with the electrical energy of the cell. In this case, the bulb uses the electrons to heat the filament in the bulb and to create light.
  • Electrical switches: In order for the electrical circuit to operate, the electricity must flow and be continuous. If there is a discontinuity in the electrical circuit, no work is necessary.
  • Electrical wiring: Electrical wiring consists of thin conductive wires that allow electrons to pass from one component to another and complete the circuit.

If you want to define the meaning of electrical conductors in the simplest way, they are materials that make it easy for electricity to flow through them. If we compare two types of material, and the first allows for a better flow of electricity through it, then the material is said to be a good conductor of electricity.

The electrical conductor allows the electrical charges to flow through them easily. Thus, in simple words, it can be said that electric current is a flow of charge. Conductivity is the characteristic of conductors to “conduct” electricity. Such materials offer little opposition or “resistance” to the flow of fees. The use of materials allows easy transfer of charges due to the free movement of e–s through them.

In general, non-metals are bad conductors or insulators. On the other hand, metals are good conductors. The poor conductor has very few numbers of free electrons and would have a high resistance to the electrical current movement. Materials such as rubber, glass, wood, etc. are poor conductors. Thus, bad conductors can be said Resistors As Components That Oppose The Flow Of Current.

In this chapter, we learned about the concept of electricity and magnetism. We learned about the electricity test in the presence of a magnetic field. We also talked about the symbols used in an electrical circuit, the concept of good and bad conductors of electricity and Battery As A Collection Of Cells Con.

  1. What is a good and bad conductor of electricity?
    A material that allows electricity to flow through easily is called a conductor. Metals, especially silver, are good electrical conductors. Materials such as glass and rubber are weak electrical conductors and are considered insulators.
  2. Why is metal the weak conductor of electricity?
    Tungsten and Bismuth are metals that are bad conductors of electricity. There are several metals, but some of them include Aluminum, Bismuth, Gallium, Indium, Lead, Thallium, Tin, Ununhexium, Ununpentium, Ununquadium, and Ununtrium.
  3. What is the unit used for the magnetic field?
    The magnetic field is defined as B and H. The SI unit H is amperes per metre and the SI unit B is Newtons per metre per ampere or teslas.
  4. What is Faraday’s law of electromagnetism?
    Faraday’s electromagnetism law describes how the magnetic field and the electrical charge combine to form the EMF (electromotive force).
  5. Why are copper wires used as connecting wires?
    Copper wires are used as connecting wires because they provide low resistance to the electron flow.

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