## 1) Definition
> _Charge is a fundamental property of matter that allows it to produce or experience electric and [[Magnetic Field]]. It is quantified by a specific value, and the smallest possible charge observed in nature belongs to elementary particles such as electrons and protons._
The charge of an **electron or proton** is:
$
1 \, e = 1.6 \times 10^{-19} \, \mathrm{C}
$
---
## 2) Types of Charges
There are two types of charges based on their nature:
- **Positive Charge**: Found in protons.
- **Negative Charge**: Found in electrons.
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## 3) Interaction of Charges
- **Like charges** (e.g., positive-positive or negative-negative) **repel** each other.
- **Unlike charges** (e.g., positive-negative) **attract** each other.
![[Pasted image 20241130103953.png]]
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## 4) Unit of Charge
The **SI unit** of charge is the **coulomb (C)**.
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## 5) Properties of Charge
### i) Quantization of Charge
Charge exists only in discrete packets and **cannot take fractional values.** The charge on any object is an integer multiple of the elementary charge:
$
q = n \cdot e
$
Where $n = 1, 2, 3, \dots$. Examples of non-allowed charges include $0.5e$, $1.5e$, etc.
---
### ii) Charge is a Scalar Quantity
- Charge does not have a direction, **only magnitude.**
- It can be added or subtracted using simple algebraic rules.
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### iii) Charge is Transferable
- Charges can **move from one object to another.**
- For instance, when an uncharged body contacts a charged body, the uncharged body acquires charge.
---
### iv) Charge is Always Associated with Mass
Charge cannot exist independently without being associated with some form of mass. **All charged particles have mass.**
---
### v) Conservation of Charge
**Charge can neither be created nor destroyed.** In any closed system, the total charge remains constant. This principle applies universally.
---
## Summary
### Key Points:
| **Concept** | **Explanation** |
| ---------------- | ----------------------------------------------------------------------------- |
| **Charge** | Property of matter that allows interaction with electric and magnetic fields. |
| **Types** | Positive (protons) and Negative (electrons). |
| **Quantization** | Charge exists in integer multiples of $e$. |
| **Conservation** | Total charge in a system is constant. |
### Significance:
Charge plays a crucial role in the study of electromagnetism and is essential to understanding phenomena like electricity, magnetism, and the forces that govern atomic and molecular structures. This concept underpins technologies like electric circuits, semiconductors, and communication systems.