Electrical Energy To Mechanical Energy: How To Convert, FAQs And Facts

Energy conversion techniques are a boon for civilization. This article discusses deeply on how to convert electrical energy to mechanical energy.

Most devices that convert electrical energy to mechanical energy contain an electric motor embedded in it that operate by the interaction of motor’s magnetic field with the electric current passing through a wire. This interaction generates a torque that causes the rotation of shaft i.e., mechanical energy.

Further insight into the energy conversion can be obtained in the following subheadings.

How to convert electrical to mechanical energy?

An electric motor is the component in several machineries and devices that aids the transformation of electrical energy to mechanical energy. The electrical energy supplied by the electric current flowing in a wire interacts with magnetic field. This interaction results in torque which rotates the coil and hence mechanical energy is produced.

Electrical energy to mechanical energy device

Several devices we come across on a daily basis converts electrical energy to mechanical energy. Here are a few:

Electric fan

When electrical energy in the form of AC (Alternating Current) is supplied to the fan, the capacitor in the fan stores energy and uses it to rotate the fan. The capacitor supplies energy to the stator windings which develops rotating magnetic field and forces the rotor (electric motor) to rotate in the direction of the magnetic field. This energy is thus transferred to the fan blades and hence mechanical energy conversion takes place.

Blender or Grinder

Blender incorporates a motor which plays the role of transforming the electrical energy supplied into the mechanical energy of the rotating blades. When the motor is active, a coupler shaft attached to the motor rotates at his speed and it consequently transferred to the blades.

If more power is supplied to the motor, the blades rotate at high speeds and vice versa.

Washing machine

Electric motor present in the washing machine converts electrical energy into rotational kinetic energy (i.e, mechanical energy) that helps in washing the clothes.

Dishwasher

Nowadays, dishwashers have become an electrical appliance commonly found in almost every household.

Dishes are cleaned by dishwasher which contains a pump that sprays high pressure water. An electric DC motor powers the pump. The water is recirculated using a filter system.

The energy transformation from electrical to mechanical energy is aided by the high voltage DC motor in the dishwasher.

Shaving trimmer

In a shaving trimmer, DC motor converts the electrical energy to mechanical energy due to which the blades of the trimmer that are movable oscillate at a quick pace. There are stationary blades which overlap with the movable blades during trimming of hair.

Braun S3 electric shaver — **Shaving Trimmer**
Image Credits: Wikimedia Commons

How motor converts electrical energy to mechanical energy?

As discussed above, an electric motor finds wide variety of applications in electric fans, household appliances, machineries, etc.

An electric motor may be powered by an AC (alternating current) source or a DC (direct current) source. Electric motor works by the principle of electromagnetism, where electric field and magnetic field interactions generate a torque that causes the motor to rotate.

Electric motor working process — **Working of an electric motor**
Image Credits: Wikimedia Commons

A motor (DC motor) comprises of a stator (magnet), a rotor (an axle with a coil mounted on it which spins at high speeds and acts as an electromagnet), a commutator or key, a power source (DC) and brushes. Whenever electric current flows through the coil (on the rotor), it generates a magnetic field as we know, current carrying electric fields generate magnetic field. This generated magnetic field interacts with the magnetic field due to the stator which in turn, results in creating torque. The torque makes the rotor spin and hence mechanical energy is produced.

Principle of conservation of mechanical energy

The statement of the principle of conservation of mechanical energy:

“If only conservative forces are doing work, the total mechanical energy of a system neither increases nor decreases in any process. It stays constant—it is conserved.”

A conservative force generally means that the work done by the force on moving an object from one point to another depends not on the path of action, but only on the initial and final positions of the object. Examples include gravitational force, electric force, etc.

The statement of principle of conservation of mechanical energy may be described in simple terms as: The sum of kinetic energy and potential energy during any part of a body’s motion is the same as the sum of kinetic energy and potential energy during anywhere else of motion. Here, total mechanical energy is the sum of kinetic energy and potential energy of the body under consideration.

Electrical Energy To Mechanical Energy: Frequently Asked Questions

Give a brief example demonstrating the principle of conservation of mechanical energy.

We know, the principle of conservation of mechanical energy is valid only for bodies in motion under the influence of conservative forces.

Consider the motion of a roller-coaster in an adventurous theme park. Neglecting friction or influence of any other non-conservative forces, gravitational force is the only conservative force acting on it.

Roller coaster energy conservation — **Mechanical Energy Conservation in a Roller Coaster**
Image Credits: Wikimedia Commons

At the topmost position, its potential energy would be at maximum and the kinetic energy would be minimum. Whereas, at the lowest position, the kinetic energy of the roller-coaster would be the maximum as it would have high velocity and the potential energy would be minimum. At any positions in between, the kinetic and potential energies would be in such a way that their sum, i.e., total mechanical energy would be a constant.

Give short notes on electromagnetic induction.

Electromagnetic induction can be described as the process by which an emf (electromotive force) is generated across a conductor placed in a varying magnetic field.
Michael Faraday was the one who discovered electromagnetic induction.
The principle of electromagnetic induction finds several applications in day-to-day lives in several devices like electric generators, transformers, motors, etc.

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Deeksha Dinesh

Hello, I am Deeksha Dinesh, currently pursuing post-graduation in Physics with a specialization in the field of Astrophysics. I like to deliver concepts in a simpler way for the readers.