Question

What is the basic principle of transformer?

Answer 1

The basic principle of a **transformer** is **electromagnetic induction**.

Here's a simple breakdown:

1. **Magnetic Field Generation**: A transformer has two coils of wire: a **primary coil** and a **secondary coil**. When alternating current (AC) flows through the primary coil, it creates a **changing magnetic field** around the coil.

2. **Magnetic Flux Linkage**: The changing magnetic field then passes through the secondary coil. This is called **magnetic flux**. Because the magnetic field is changing, it induces a **voltage** in the secondary coil (this is **electromagnetic induction**).

3. **Voltage Induction**: The voltage induced in the secondary coil depends on the number of turns (loops of wire) in the primary and secondary coils. This is described by the **transformer equation**:

   $$
   \frac{V_1}{V_2} = \frac{N_1}{N_2}
   $$

   where:

   * $V_1$ and $V_2$ are the voltages in the primary and secondary coils, respectively.
   * $N_1$ and $N_2$ are the number of turns in the primary and secondary coils, respectively.

   So, if the number of turns in the secondary coil is greater than in the primary, the transformer will **step up** the voltage. If the number of turns in the secondary coil is fewer, it will **step down** the voltage.

### Key Points:

* **AC current** is used because the changing current creates a changing magnetic field, which is essential for inducing voltage.
* The transformer works on the principle of **electromagnetic induction**, which means the energy is transferred between the two coils without any physical connection.
* The voltage change depends on the ratio of the number of turns in the coils.

This process allows transformers to increase or decrease the voltage for various applications, such as power transmission, distribution, and adapting to different devices.