Question

1. explain what makes the armature in an electric motor rotate?

Explanation:

When current flows through the armature coil, it creates a magnetic field. This interacts with the magnetic field from the permanent magnet (or stator in some cases). According to the Lorentz force law ($\vec{F} = q(\vec{v}\times\vec{B})$ for a charged particle, and extended to current - carrying wires as $F = ILB\sin\theta$ where $I$ is current, $L$ is wire length, $B$ is magnetic field, and $\theta$ is the angle between the wire and the field), the forces on different sides of the coil are in opposite directions. This causes a torque that makes the armature rotate.

Answer:

The interaction between the magnetic field created by the current - carrying armature coil and the external magnetic field (from a permanent magnet or stator) results in forces (due to the Lorentz force on current - carrying conductors) that produce a torque, causing the armature to rotate.