# Mechanical Energy to Electrical Energy

Energy conversion techniques are a boon to civilization. This article discusses in depth how to convert electrical energy into mechanical energy.

Most devices that convert electrical energy into mechanical energy have an electric motor that is driven by the interaction of the motor’s magnetic field with an electric current passing through a wire. This interaction produces a torque which causes the rotation of the shaft i.e. mechanical energy.

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

## How to convert electricity to mechanical energy?

An electric motor is a component in many machinery and equipment that helps convert electrical energy into mechanical energy. The electric energy supplied by an electric current flowing in a wire interacts with the magnetic field. This interaction results in torque which rotates the coil and hence mechanical energy is generated.

## electrical energy to mechanical energy equipment

Every day we come across many devices which convert electrical energy into mechanical energy. Here are some:

### electric fan

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

### blender or grinder

The blender includes a motor that plays the role of converting the electrical energy supplied by the rotating blades into mechanical energy. When the motor is energized, a coupler shaft attached to the motor rotates at its own speed and as a result it is transferred to the blade.

If more power is supplied to the motor, the blades spin at a faster rate and vice versa.

### Washing machine

The electric motor present in the washing machine converts electrical energy into rotational kinetic energy (ie mechanical energy) which helps in washing clothes.

### dish cleaner

Nowadays, the dishwasher has become an electrical appliance found in almost every home.

Dishes are cleaned by a dishwasher that has a pump that sprays high-pressure water. An electric DC motor powers the pump. The water is re-circulated using a filter system.

The energy conversion from electrical to mechanical energy is assisted by a high voltage DC motor in the dishwasher.

### shaving trimmer

In a shaving trimmer, a DC motor converts electrical energy into mechanical energy which causes the blades of the trimmer to oscillate at high speed as it moves. There are fixed blades that overlap with the movable blades during hair trimming.

## How does a motor convert electrical energy into mechanical energy?

As discussed above, an electric motor finds a wide variety of applications in electric fans, home appliances, machinery, etc.

An electric motor can be powered by an AC (alternating current) source or a DC (direct current) source. The electric motor works on the principle of electromagnetism, where the electric field and magnetic field interaction generate a torque that causes the motor to spin.

A motor (DC motor) consists of a stator (magnet), a rotor (an axle with a coil that spins at high speed and acts as an electromagnet), a commutator or key, a power source ( dc) and brush. Whenever an electric current flows through the coil (on the rotor), it generates a magnetic field. As we know, electric fields carrying current generate a magnetic field. This generated magnetic field interacts with the magnetic field due to the stator resulting in torque. Torque spins the rotor and hence mechanical energy is generated.

## principle of conservation of mechanical energy

Statement of the principle of conservation of mechanical energy:

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

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

The statement of the principle of conservation of mechanical energy can be described in simple words: the sum of the kinetic energy and potential energy during any part of the body’s motion is the same as the sum of the kinetic energy and potential energy during any part of the motion it happens. Here, the total mechanical energy is the sum of the kinetic energy and potential energy of the body in question.

## Give a brief example showing 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 speed of a roller-coaster at an adventure theme park. The force of gravity is the only conservative force acting on it, disregarding the friction or effect of any other non-conservative forces.

In the topmost case, its potential energy will be maximum and kinetic energy will be minimum. Whereas, at the lowest position, the kinetic energy of the roller-coaster will be maximum as it will have high velocity and the potential energy will be minimum. In any case in between, the kinetic and potential energies will be such that their sum, that is, the total mechanical energy, will be constant.

## Give short notes on electromagnetic induction.

• Electromagnetic induction can be described as the process by which an emf (electromotive force) is produced in a conductor placed in a varying magnetic field.
• Electromagnetic induction was discovered by Michael Faraday.
• The principle of electromagnetic induction finds many applications in day to day life in many devices such as electric generators, transformers, motors etc.
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