Concepts of Physics Used in Industrial Machines: Electric Motors

In order to understand well what machines we need we must know about the concepts of  physics used in industrial machines . There are many of these that can be learned without being physical and that will help in a faster selection of industrial machinery.

Concepts of physics used in industrial machines

Law of Lorentz

This is the principle that electric motors follow to function . It is a basic principle and explains how forces are created in electromechanical systems, which are the ones that use electric motors. The complete description for each type of electric motor depends on its components and its construction and therefore, the equation changes according to the type.

This law talks about the force exerted by the electromagnetic field and that it receives a charged particle or an electric current. That is, it is the force and follows this equation:

{\displaystyle \mathbf {F} =q(\mathbf {E} +\mathbf {v} \times \mathbf {B} )}


The  current  is continuous flow of electrical charge passing through a conductor. It does so between two points of different potential and electrical charge and does not change direction with time. That is to say, electric charges always circulate in the same direction. However, in  alternating current , they can change. It is one of the main concepts of physics used in industrial machines.

Applying this concept to the different electric motors, we have to:

The DC motor. This type of motor converts electrical energy into mechanical energy by means of a rotary movement. This rotary movement is generated as a consequence of the magnetic field.
The AC motor works by means of electric power. This motor converts electrical energy into turning force by means of magnetic fields .

Universal current

There are other types of electric motors different from the previous ones. The electric motors of universal current work with both voltages, those of direct current or alternating current. The electrical circuit of the motor has only one way for the current to pass and its potential is greater. They have, therefore, greater flexibility when it comes to overcoming inertia at the moment of rest.

Power of an electric motor

The power a very important value to know when choosing engine. It is measured in kW and hp. Many manufacturers of industrial machines let you choose, in their web pages, between a minimum and maximum range. From there you can choose between the options that comprise that range.


There are several types: nominal torque, motor, torque resistant and calculation. It is measured in Nm. The pair is a numerical range that depends on many other elements and has a vital importance. It is measured in Nm. It will be the first data that we will have to have clear.

The speed of rotation

The value of the rotation speed in electric motors is measured in revolutions per minute (rpm) and rad.mid-1. As in other values ​​that are used to choose between one motor and another, a minimum and maximum range are used.