Question

What unit is current?

Answer 1

The unit of **electric current** is the **ampere**, which is usually shortened to **amp** and symbolized by **A**.

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###  What is Electric Current?

Electric current is the **flow of electric charge**—typically carried by moving electrons in a wire. It tells us **how many charges are passing through a point in a circuit each second**.

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### ⚙️ Why the Ampere?

The **ampere (A)** is defined as:

> **One ampere** is the current that flows when **one coulomb (C) of charge passes a point in a circuit per second**.

In other words:

$$
1\ \text{A} = 1\ \frac{\text{C}}{\text{s}}
$$

Where:

* **A** = ampere (unit of current)
* **C** = coulomb (unit of electric charge)
* **s** = second (unit of time)

So if 5 coulombs of charge pass a point in 1 second, the current is 5 amperes.

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###  Types of Current

There are two main types of electric current:

1. **Direct Current (DC):** Flows in one direction (e.g., batteries).
2. **Alternating Current (AC):** Changes direction periodically (e.g., household power).

Regardless of type, the unit remains **ampere (A)**.

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###  Measuring Current

Current is measured with a device called an **ammeter**, which is connected **in series** with the circuit so it can measure the full current flowing through.

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###  Bonus: Related Units

* **Milliampere (mA):** 1 mA = 0.001 A (used for small currents like in electronics)
* **Microampere (μA):** 1 μA = 0.000001 A (used in very sensitive measurements)

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Let me know if you'd like an example or a visual explanation of how current works!