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Understanding electric charge becomes much simpler when we connect it with things we experience daily. Instead of memorising definitions, you will understand it like a concept you’ve known all your life - just seen from a scientific lens. So let’s break it down step-by-step, like we would in a friendly classroom session.
And the rule is simple:
Like charges repel.
Unlike charges attract.
This is not a rule invented by humans. Nature behaves this way on its own. Every atom around you follows this.
Think of charges like people:
This analogy helps because electric charge is really about interaction, not size or weight. Tiny particles like electrons and protons behave differently only because their charges differ.
Electrons have negative charge, protons have positive charge, and neutrons have no charge - just like the quiet friend in a group project.
Electric charge is not created or manufactured. It is a natural property of particles.
Electrons did not “decide” to be negative; they simply are.
Scientific measurements reveal:
| Particle | Charge |
|---|---|
| Electron | –1.6 × 10⁻¹⁹ C |
| Proton | +1.6 × 10⁻¹⁹ C |
| Neutron | 0 C |
This fixed value is called the elementary charge, the smallest unit of charge that exists freely.
Everything else is built using multiples of this.
Money comes in positive and negative forms too - you either have balance (+) or you owe money (–).
Here’s how the analogy works:
Positive charge = surplus of money
Negative charge = loan or deficit
Neutral object = no money owed, no extra balance
If electrons move into an object - it becomes negatively charged (like taking a loan).
If electrons move out of an object - it becomes positively charged (like clearing debt or having extra money after repayment).
This analogy is powerful because:
Charge can transfer just like money transfers.
Total charge is conserved just like total money in a closed group stays constant.
No new charge is created - it just moves from one place to another.
An object becomes charged when there is an imbalance of electrons.
There are three main ways:
When you rub a balloon on your hair, electrons shift from one surface to another.
Your hair loses electrons - becomes positively charged.
Balloon gains electrons - becomes negatively charged.
That’s why the balloon sticks to the wall - opposite charges attract.
If a charged object touches a neutral object, electrons flow until both have the same charge.
Exactly like sharing water between two containers until the levels equalise.
3. Induction (Without Touching)
A charged object can force charges to shift inside a nearby object without touching it.
It’s like someone entering a classroom and everyone rearranging their seats because of them - influence without contact.
Many students mix up current and charge, thinking they mean the same thing.
Let’s apply a quick PAS here:
Problem:
Students often think electric charge is the same as electric current because both involve electrons.
Agitate:
This leads to confusion in circuits, wrong numerical answers, and difficulty imagining what is actually moving inside wires.
Solution:
Remember this:
Charge is the stuff that moves (electrons).
Current is the rate at which charge moves.
Analogy:
Charge = water in a pipe
Current = flow rate of the water
Once this is clear, circuit concepts become much easier.
This is a simple example of charging by friction.
What actually happens:
As you walk on the carpet, your feet pick up electrons.
Your body becomes negatively charged.
When you touch a metal doorknob, electrons jump from you to the metal.
This sudden movement is the shock.
Why metal?
Metals allow electrons to move freely - they give the electrons a path to escape.
Fun fact:
This discharge can be around 3,000-4,000 volts, but the current is extremely small, so it’s safe.
To understand electric charge flow, imagine a water system:
Electric charge = water
Voltage = pressure pushing water
Current = flow rate of water
Resistance = narrow pipe slowing water
This analogy helps students visualise how electricity behaves inside circuits.
Example:
If you increase voltage (pressure), more charge (water) flows.
If resistance increases (pipe gets narrow), charge flow decreases.
This is exactly what Ohm’s Law represents:
Voltage = Current × Resistance
(V = IR)
Metals contain free electrons - electrons that are not tightly bound to atoms.
You can visualise a metal as a crowded hall where atoms are seats and electrons are students moving freely between them.
When voltage is applied:
Electrons start drifting
The drift velocity is small (only a few millimetres per second)
But the signal moves very fast - close to the speed of light
This is like students passing a message across the hall:
The message moves quickly, even if each student moves only a little.
This is known as the law of conservation of charge.
Example analogy:
Imagine a classroom with 50 chairs.
Students can switch chairs, move around, or exchange places -
but the total number of chairs remains the same.
Similarly, charges move but the total charge in a closed system stays constant.
Objects want to return to neutrality - a balanced state with equal numbers of positive and negative charges.
Just like people feel relieved when debts are cleared, objects try to neutralise:
A negatively charged object gives away extra electrons.
A positively charged object attracts electrons.
This “urge for balance” explains lightning too.
Thunderclouds are like giant batteries in the sky.
Inside clouds:
Ice particles rub against each other.
The top of the cloud becomes positively charged.
The bottom becomes negatively charged.
The ground is usually positive relative to the cloud bottom.
When the difference becomes very large:
A tremendous discharge occurs.
This is lightning.
A lightning bolt carries around 30,000 amperes.
Temperatures can reach 30,000°C, hotter than the Sun’s surface.
The same principle you see when rubbing a balloon - just on a massive scale.
Conductors
Allow charge to move freely.
Examples: copper, aluminium, silver, saltwater.
Analogy: A playground with open gates - students can move anywhere.
Insulators
Do not allow charge to move easily.
Examples: plastic, wood, rubber, glass.
Analogy: A classroom with locked doors - students can’t move between rooms.
Semiconductors
Behave like insulators at low temperature but conduct when energy increases.
Examples: silicon, germanium.
Analogy: A student who is quiet until they gain confidence - then they participate more.
Problem:
Students often believe that protons move in wires when current flows.
Agitate:
This causes misunderstandings in circuit diagrams, direction of current, and electron movement.
Solution:
Protons never move in a metal wire.
Only electrons move.
Teachers define conventional current as flowing from + to -, but this is only a naming convention.
In reality, electrons move from - to +.
Electric charge is not a chapter. It’s everywhere around you.
1. Photocopiers and printers
Use electric charge to attract toner particles onto paper.
2. Touchscreens
Your finger changes the charge distribution on the screen, which registers your touch.
3. TV and phone displays
Liquid crystals respond to electric charges, changing colour and brightness.
4. Static cling on clothes
When clothes tumble in a dryer, charge builds up. Felt painfully in winters.
5. Electric fish (like the electric eel)
Generate electric charges up to 600 volts for hunting and defence.
6. Cars and fuel pumps
Fuel nozzles are grounded to prevent charge buildup - avoiding sparks.
Engineers and scientists use charge concepts daily.
1. Pollution control
Electrostatic precipitators remove dust from power plant emissions.
Dust particles become charged and are attracted to collection plates.
2. Spray painting cars
Charged paint droplets stick to the car body uniformly - reducing waste by up to 50%.
3. Air purifiers
Use charged plates to trap dust and pollen from the air.
4. Semiconductor industry
Uses controlled charge movement to build transistors, the building blocks of all electronics.
Imagine:
A classroom full of students = neutral object
A few extra students enter = negatively charged
A few students leave = positively charged
Now imagine the teacher (voltage) giving instructions:
Students start moving in one direction (current).
Obstacles in their path (resistance) slow them down.
This analogy makes all electric concepts blend together naturally:
Charge
Voltage
Current
Resistance
Flow
Many students depend on memorising rules like “positive attracts negative.”
But electricity becomes much easier when you picture it.
Charge is like tiny movable marbles.
Voltage is the push that moves them.
Resistance is the difficulty of their path.
Current is how many marbles pass in one second.
Once you imagine this, every concept - from circuits to electrostatics - becomes intuitive.
Problem:
Students panic when they see formulas involving charge and current.
Agitate:
This leads to exam fear and careless mistakes.
Solution:
Remember the relationships visually:
Q = It - Charge = Current × Time
(Imagine water flowing for a certain time.)
I = Q/t - Flow rate
V = W/Q - Voltage is energy given per charge
(Like energy spent on each student.)
These formulas are not abstract - they simply describe real behaviour.
Let’s summarise everything in simple, connected points:
Charge is a property of particles.
It comes in + and - types.
Electrons move; protons don’t.
Charge moves from one object to another - it’s never created.
Voltage pushes charge.
Current is the flow rate of charge.
Resistance opposes charge flow.
Conductors allow movement; insulators block it.
All of these ideas appear in daily life.
With these connections, electric charge stops being a chapter to memorise - it becomes a behaviour you can feel, see, and relate to.
Electric charge is one of the simplest concepts in physics when understood with analogies and real-life visuals, not memorised definitions. The more examples you see around you - static shocks, touchscreens, photocopiers, lightning - the more natural the concept feels.
When you understand charge, the entire world of electricity becomes easier: current, potential difference, circuits, series connections, Ohm’s Law, magnetism, and even electronics.
Keep observing, keep visualising, and you’ll find electricity far more intuitive than it appears in textbooks.
If you want to practice this topic, you can take a quiz in Curious Corner for better practice.
*Note: You must register yourself to access the quizzes.*
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