Let’s begin with an alluring stuff! Ever wondered what happens in between the time you turning ON a switch and a Tube light glowing ❓❓❓…..It’s due to ‘Electricity’, everybody says! We cannot escape certain things in our routine. Electricity is one among them.
But… what Electricity exactly is ??? Let’s not harp on the same phrase now, ‘flow of electric charges’.
Sometimes, we need not be convinced with the postulates of some people just because they are well known. So keep exploring Science!
How does Electricity differs from Current ???….. To understand this, we got to travel a little deeper into the Basic Building Blocks of life and matter – ATOM.
- These are very tiny particles (about 300 picometers long) which make up a matter. But, they are not small enough to explain about electricity!
- Every living and non living things are composed of Atoms.
- As known, an Atom is made of a trio:
1. Protons – positively charged
2. Electrons – negatively charged
3. Neutrons – Neutral
Protons + Neutrons -> Nucleons (since they make up the Nucleus).
These trio serve a purpose.
- No. Of protons or electrons tells the chemical composition the atom represents.
- Neutrons bind the protons inside nucleus and also decides the isotopes.
Let’s consider Bohr’s Atomic Model:
According to Bohr, an atom has a positively charged Nucleus at the centre. And electrons are found orbiting the nucleus in their own orbits.
And now…. coming to to electricity, An atom in general, is Electrically Neutral, i.e.,
No. of protons = No. of electrons
In general, electricity is the ‘flow of charges’. Now, what is a charge???
Charge is a property of matter. Just as you measure your mass, you can measure charge. It is of 2 kinds:
POSITIVE CHARGE: if an atom has more protons than electrons, it is said to be positively charged.
NEGATIVE CHARGE: if an atom has more electrons than protons, it is said to be negatively charged.
As said earlier, electricity is the ‘flow of charges’. The charges need to be moved to produce electric current. But, how to move the charges????
We know that…to make a thing move, a force is need to be exerted on it. Similarly, to make charges move/flow, a force is applied on it. This is called as ‘Electrostatic Force’
It is the force between two charges. It is the reason behind the repulsion of like charges and attraction of unlike charges.
In atoms, with enough electrostatic force, the electrons in each shell are bound by the nucleus. Here, by Coloumb’s law, the amount of force exerted by the nucleus on the electrons decreases with increase in distance between them. That is, an electron in the first shell is tightly bound, since it is closer to the nucleus. The electrons in the last shell, the Valence electrons, are very loosely bound to the nucleus and they require only a negligible force to free them. So, if we kick out these electrons, there will be a movement of charges, hence the current.
Now, consider the earlier scenario….how the tube light glows when the switch is turned ON ????
Of course the connection between the switch board and the light is wired, say copper wire. The wire is wholly made of copper atoms as well. Since the atoms are closely packed, a free electron is obtained by applying a force. This force is often called as ‘Voltage’ or ‘ potential’. Let’s learn about them in the upcoming posts✌.
- Here, turning ON a switch is equivalent to applying voltage, as we exert a force.
- This free electron floats in free space until it is pulled by the surrounding charges in vicinity.
- Thus the free electron finds a new atom.
- Now, again the negative charges of that electron ejects another valence electron from the atom.
- Thus, the free electron keeps moving from one atom to another in free space.
- This movement continues across the wire till it reaches the tube light.
- A tube light is a fluorescent tube whose inner walls are coated with Phosphor.
- Once the free electron reaches the tube light, the mercury vapour inside the tube light, is excited and produces a short wave UV light.
- This UV light causes the inner walls of the lamp to glow!✨
And ultimately…..the process explained above is the generation of Electric Current. Then, how does Current differ from Electricity???
Consider the literal meaning of current….
Imagine, from a fountain, when the water flows very fast, we say that the water has a ‘Current’ in a specific direction.
Thus, ‘Current’ is the ‘movement’ of charges. And…
‘Electricity’ is the ‘amount’ of charges moving.
Stay up for more updations!