🌟 Electric Charge: The Invisible Power Around Us
Have you ever noticed your hair standing up after combing it on a dry day, or felt a tiny shock while touching a metal door handle? Lightning flashing across the sky during a thunderstorm is another dramatic example. All these everyday experiences happen because of electric charge.
Electric charge is a fundamental property of matter. Although we cannot see it directly, its effects are visible everywhere—from small sparks to powerful lightning bolts.
⚡ What Is Electric Charge?
Every object around us is made up of tiny particles called atoms. Inside each atom are:
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Protons (positively charged)
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Electrons (negatively charged)
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Neutrons (no charge)
Normally, an object has equal numbers of protons and electrons, so it is electrically neutral. But when electrons move from one object to another—often due to rubbing—an imbalance occurs, and the object becomes charged.
✨ Types of Electric Charges
There are two kinds of electric charges:
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Positive charge
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Negative charge
Their interaction follows a simple rule:
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Like charges repel each other
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Unlike charges attract each other
For example:
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Two positively charged objects push each other away.
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A positively charged object attracts a negatively charged one.
🔌 Conductors and Insulators
Not all materials behave the same way when electric charge is involved.
🧲 Conductors
Conductors are materials that allow electric charges (electrons) to move freely through them.
Examples:
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Metals like copper, aluminium, iron
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Human body
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Earth
Because charges can move easily, when a conductor is charged, the charge spreads quickly over its entire surface.
🪵 Insulators
Insulators are materials that do not allow electric charges to move freely.
Examples:
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Plastic
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Glass
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Rubber
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Wood
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Porcelain
When an insulator is charged, the charge stays at the place where it was produced. That is why a plastic comb rubbed on dry hair can attract tiny bits of paper, while a metal spoon usually cannot.
🔍 Why Do Objects Get Charged?
Charging mainly happens due to the transfer of electrons:
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An object losing electrons becomes positively charged
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An object gaining electrons becomes negatively charged
⚠️ Important:
No new charge is created during rubbing—charges are only transferred from one object to another.
📘 Basic Properties of Electric Charge
Electric charge has some important properties that help us understand how electricity works.
1️⃣ Additivity of Charge
Electric charge is a scalar quantity, which means it has magnitude but no direction.
If a system has many charges, the total charge is the algebraic sum of all individual charges.
Example:
If charges are +2 C, −3 C, and +5 C,
Total charge = +2 − 3 + 5 = +4 C
2️⃣ Conservation of Charge
Electric charge is conserved.
This means:
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Charge can neither be created nor destroyed
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It can only be transferred from one object to another
Even when charges move or redistribute within a system, the total charge remains constant.
3️⃣ Quantisation of Charge
Electric charge exists in discrete packets, not in continuous amounts.
The smallest possible unit of charge is the charge of an electron or proton, denoted by e.
where:
= total charge
= integer (positive or negative)
This means every observable charge is an integral multiple of e.
🌈 Why Electric Charge Matters
Electric charge is the foundation of:
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Electricity and electronics
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Lightning and thunderstorms
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Modern technology like mobile phones, computers, and medical devices
Understanding electric charge helps us explore deeper ideas like electric fields, electric current, and electromagnetic waves—all of which shape the modern world.