## Explanation

### Energy Transformation in an Operating Electric Motor

In an operating electric motor, the primary energy transformation is from **electrical energy to mechanical energy**. This process is fundamental in countless applications, ranging from household appliances to industrial machinery.

To understand this process, let's delve into the **underlying physics**. When an electric current flows through the motor's windings, it generates a magnetic field. This magnetic field interacts with the permanent magnets or other windings within the motor, producing a force according to **Lorentz force law**:

Where:

- $\vec{F}$ is the force experienced by a charge
- $q$ is the charge
- $\vec{E}$ is the electric field
- $\vec{v}$ is the velocity of the charge
- $\vec{B}$ is the magnetic field

This force generates a **torque** on the motor's rotor, leading to rotational motion. The relationship between the torque ($\tau$) and the magnetic field can be described by the formula:

Where:

- $\vec{m}$ is the magnetic moment
- $\vec{B}$ is the magnetic field

**Mechanical energy** is then harnessed to perform work, driving different mechanisms as intended by the design of the motor.

To summarize, the essential transformation in an operating electric motor is from **electrical energy** to **mechanical energy**, enabling the conversion of electric power into kinetic energy.