Solenoid – Definition and How does it Work?


Solenoids are basically coils of wire. These generate a magnetic field which strives a force over a metallic element. This happens when we apply the electric current to the solenoid.

Solenoids help the energy to convert into action instantly. Therefore, these work decently for those applications which require immediate action.

Solenoid in Physics

A solenoid is a basic term for a coil of wire that we use as an electromagnet. We also refer to the device that can convert electrical energy into mechanical energy as a solenoid.

Actually it generates a magnetic field for creating linear motion from the electric current. With the use of a magnetic field.

solenoid Basic applications of the solenoids are to be used in switch for power. Like the starter in any vehicle. A valve in a sprinkler system is also an example.

How does Solenoid work?

As discussed above a solenoid is a coil of wire. It is in the shape of a corkscrew and wraps around a piston. On the other hand, it is made up of iron. Likely in all the electromagnets. When an electric current passes through the wire, a magnetic field generates.

More importantly, electromagnets are better as compared to the permanent magnets because they can be switched on and off by the removal of the electric current or by the application.

This makes them more useful like switches and valves and also allows them automated entirely. Likewise, all other magnets and activated solenoid’s magnetic field has both positive and negative poles that result in attracting or repelling material sensitive to magnets.

Electric Solenoids

The starter solenoid in an automobile ignition system acts as a relay. This brings the metal contacts at a place that results in closing a circuit. When the motorcar’s ignition activates, the starter solenoid receives a small electric current, basically by the turn of the key.

Then the solenoid’s magnetic field pulls on the contact, and this process closes the circuit between the starter motor and the car’s battery. In order to maintain the circuit, the starter solenoid needs a constant flow of electricity. When the engine starts then the solenoids are not most active because the engine is self-powering.

Uses of Solenoids

Solenoids are extremely useful and incredibly versatile. We can find them almost everywhere from doorbells to paintball guns and even in automated factory equipment. In doorbell, the audible sound generates because the metal piston strikes at a tone bar.

The magnetic field of solenoids is the force that moves the piston and this force receives the electric current when we ring the doorbell.

Functions of Solenoid

As the electric current passes through the solenoid’s coils, the creation of a magnetic field takes place. The magnitude’s strength is measured by the number of coils are featured by the solenoid.

The armature in a solenoid is movable: therefore, a voltage passes through the coils and the armature increases the flux linkage by its movement.

This happens due to the closing of the air gap between the two cores which are movable or the armature. They come with the spring so that the voltage is switched off to the solenoid, and then it gets back to its initial position.

Uses of Solenoid

The solenoids are useful in many applications, from appliances to electron hobbies. They are usually found in the applications that require a feature that can automatically turn the appliance on or off. For example, an electric torch or an engine kill switch commonly used in motorbikes nowadays.

Solved Question for You

Ques. Solenoids are a coil of wire, we use as an?

(A). Electromagnet.
(B). Piston.
(C). Wire.
(D). Coil.

Ans. (A). Electromagnet.

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