Question

What is the principle of DC motor?

Answer 1

The principle of a **DC motor** is based on **electromagnetic induction**. When a current-carrying conductor (such as a wire) is placed in a magnetic field, it experiences a force. This force is called the **Lorentz force**. The direction of the force is given by **Fleming's Left-Hand Rule**, which states:

- **Thumb**: Direction of force (motion of the conductor)
- **First Finger**: Direction of the magnetic field
- **Second Finger**: Direction of the current

In a **DC motor**, the main parts are:
1. **Armature**: A coil of wire that carries current.
2. **Field magnet**: A permanent magnet or electromagnet that creates a magnetic field.
3. **Commutator**: A rotating switch that reverses the current direction to ensure continuous rotation.

### How it works:
1. **Current flow**: When current flows through the armature coil, it interacts with the magnetic field produced by the field magnet.
2. **Force production**: The interaction between the current in the armature and the magnetic field creates a force on the armature, causing it to rotate.
3. **Commutator action**: The commutator reverses the direction of current in the armature windings after each half-turn. This reversal keeps the armature rotating in one direction.

The continuous interaction of the current in the armature with the magnetic field causes the armature to rotate and convert electrical energy into mechanical energy.

This is the basic principle behind how a DC motor works.