Basic Electricity Concepts

Published:   July 1, 2024


So for now( 2018 AD) we human believe that electricity is flow of energy via electron from -ve(explained below) terminal to +ve(explained below) terminal, it is just that. The simple way to get this flow of energy is by using the batteries, now lets start go to deep down.

How did humans figured out electricity ?

  • Lots of things around us exhibit this energy flow.
  • Lightning, static electricity etc.

Human figured out electricity by rubbing glass rod with silk cloth

  • When people were figuring out these weird behaviours around us, they found that “When we rub the glass rod with silk cloth, glass gets a different type of behaviour and silk gets different one”.
  • They also saw when they rub the rubber-rod with cat-fur the rubber-rod got different behaviour & cat-fur got different one.
  • Similarly when they rub the amber with fur, the amber got different behaviour and fur got different one.
  • Also when they rub the ebonite with fur, ebonite has different behaviour and fur has different one.

What are positive and negative charges, why is one called positive & other negative?

  • Glass & silk cloth gets different behaviour after rubbing them together.
  • They named them positive & negative charges. They could’ve named it as A and B or anything else, but they named it as positive and negative. There is no reason behind it, it’s just a convention that people have come up with.

What was positive & negative in above glass rod and silk cloth observation ?

  • The glass rods now attracts a conductor, silk cloth repels the conductor
  • So they named glass rod as positive charge and silk cloth as negative charge.
    • They could’ve named it as A and B, but they named it as positive and negative or any two names.
  • So they named glass rod as positive charge and silk cloth as negative charge.
    • They could’ve named it as A and B, but they named it as positive and negative or any two names.

Why does rubbing cause this behaviour ?

  • Rubber attracts electrons more than animal fur.
  • So while rubbing atoms of rubber pull electrons from the atoms of animal fur.
  • Some particle attracts electron and some lose it up
  • Similar when you comb your hairs, the comb gets +ve charge, it losses electron and hairs attract them.

What is an electron ?

  • Electron is the basic particle we know, that explains the flow of electricity.
  • It is a negatively charged particle. Remember negative charge is just a convention, it could’ve been named as A or B, but it is named as negative.
  • These are small particles studied in the field of quantum physics.
  • Like matter has mass, the electron has charge.
  • Charge of electron is calculated to electron is 1.6 * 10^-19C

Can we see electron ?

  • No, we can’t see electrons, they are very small particles.
  • Again goes to realm of quantum-physics, where we can’t see things, but we can predict their behaviour.
  • Also these quantum particles exhibit wave-particle duality, they behave as wave and particle both.
    • We can make an approximation of their positions nothing more afaik.

What is charge

  • Charge is the fundamental property we take that it exists(again we prove things taking this as base behaviour that we see).
  • Charge is the property of matter to interact with electromagnetic fields, analogous to masses in gravitational fields (but, much stronger!)
  • It was calculated by Oil_drop_experiment and we take that number.
    • Charge is particle is said to be q(charge) = n * e(electron) or q = e + e … n times
    • Experimentally, it was found that charge of electron is 1.6 * 10^-19 C

Why q = n * e ?

  • It comes from quantization of electric charge.
  • Humans found that the charge of any object is multiple of the charge of electrons.
  • It’s like saying that you can’t have 1.5 electrons, you can have 1 or 2 electrons.
  • The smallest indivisible unit of charge is the charge of an electron (e)

How much is 1C of charge ?

  • q = n * e

What is resistance ?

  • Resistance is the property of a conductor to resist the flow of electrons.
  • It is measured in ohms.
  • It is denoted by R.

What is voltage

  • For energy to flow from one point to another, there should be a difference in energy level.
  • This difference in energy level is called voltage.
  • When there is difference in energy level, the energy via electric field flows using electrons in the conductor

What is current ?

  • This flow of electrons is called current.
    • Electrons themselves don’t move, they just push each other.
    • It’s like a chain of people, where one person pushes the other and so on. Energy is transferred from one person to another.
  • Current = Voltage / Resistance.
  • Current flows from high electric potential to low electric potential.
  • Current of 1 ampere (A) means that 1 coulomb of charge passes through a point in the circuit each second.

What is high electric potential and low electric potential ?

  • High electric potential is where there is more energy, and low electric potential is where there is less energy.

How does this high electric potential and low electric potential is created ?

  • To get this energy, humans do various things.
  • Humans found that moving magnet near the conductor also generates this electric field.
    • This is the principle behind the generator.
    • This electric field is then moved from power station to our homes, where we use it to power our devices.
    • This electric field flows via conductor wires like copper & runs our devices.
  • In large power-stations humans move conductors near the magnet(magnetic field).
    • Now how to move the conductor near the magnet, we use the energy generated by falling of water, or by burning of coal, or by nuclear reaction etc.
    • Keeping a strong magnetic field induces high electric potential in the conductor.
    • This high electric potential is then moved to our homes via conductor wires like copper.

What is a battery ?

  • Battery is the device that stores energy in it.
  • Energy is stored in the form of chemical energy.

Let me know if you have any questions or comments.
It will help me to improve/learn.

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