Difference Between Solenoid and Electromagnet

Main Difference – Solenoid vs. Electromagnet

The terms solenoid and electromagnet are closely related. The main difference between solenoid and electromagnet is that solenoid is the name given to a long and narrow helical loop of wire, whereas an electromagnet is a magnet whose magnetic properties depend on an electric current. Most often, electromagnets are constructed using solenoids.

What is a Solenoid

A solenoid refers to a wire coiled in a helical shape, as shown below:

Difference Between Solenoid and Electromagnet - Solenoid

A solenoid

If the wire is long and thin, when a current is sent through the wire a uniform magnetic field forms inside the solenoid. The magnetic field strength B for this uniform field can be given by:

B=\frac{\mu_0NI}{l}

where N is the number of turns in the coil, I is the current and L is the length of the solenoid. \mu_0 is the permeability of free space, given by \mu_0= 1.26 × 10-6 m kg s-2 A-2. When the solenoid is palced in a material with a relative permeability \mu_r, the \mu_0 term is replaced by \mu_0\mu_r, where \mu_r is the relative permeability of the material.

What is an Electromagnet

An electromagnet is a magnet whose magnetic properties are produced by an electric current. When the current is switched off, the electromagnet no longer displays magnetic properties.

The simplest way to make an electromagnet is to make a solenoid, pass current through it and then place a piece of soft iron inside the solenoid. Due to the high relative permeability of soft iron, the magnetic field formed would be much stronger. Note that the wires need to be insulated: if they make direct contact with the iron core, the current will simply conduct through the iron core! Often, if you look at electromagnets found inside various appliances, it seems as though the copper wires are not insulated. However, in these cases they have been coated with an insulating material.

The rod of soft iron placed inside the solenoid would behave like an ordinary bar magnet when the current is switched on. The polarity of this electromagnet can be described by the right-hand grip rule. If you grip the solenoid so that your fingers curl around in the direction of current flow through the turns of the solenoid, your thumb will point to the “North” pole of the electromagnet.

Difference Between Solenoid and Electromagnet - Right_Hand_grip_Rule

The right-hand grip rule

Difference Between Solenoid and Electromagnet

What it means

A solenoid is a long, thin helical loop of wire.

An electromagnet is a magnet whose magnetic properties depend on an electric current.

Relationship

If a solenoid is made to conduct a current, it would become an electromagnet.

However, wires forming an electromagnet do not necessarily need to have a solenoid shape.

Image Courtesy

“A three-dimensional rendering of a solenoid.” by Zureks (Transferred from en.wikipedia to Commons) [Public Domain], via

“The right-hand grip rule” by Right_hand_rule_simple.png: Original uploader was Schorschi2 at de.wikipedia [Public Domain], via

About the Author: Nipun


Related pages


adjectives attributive and predicativediamagnetic vs paramagneticdefinition of centriolenonpolar molecule definitionwhat is indefinite adjectivesdiabetes insipidus and diabetes mellituscompare atp and adpwhat is a sister chromosomeisopropyl alcohol molecular formulawhat is coelenteratealpha d fructose structureketose testdifference between depression and dysthymiatuberculoidradial body symmetrytypes of essays expositoryleast count of vernier caliper in mminformal report meaningmaize and corn differencetachycardia fibrillationwhat is a vinyl halidedifference between poetry and prosewhat does monologue mean in literaturemeristematic definitiondifference between hair smoothing and straightening treatmentpositive and normative statement examplesstatic friction kinetic frictionphysical and chemical properties of hydrocarbonscompton effect and photoelectric effectintrons and exons in dnatypes of syngamydifference between oat and wheat branwhat is dyspnea definitiondifference between a hyphen and a dashwhat is the different between lime and lemonnemesis what does it meantone and mood in poetryflu symptoms vs food poisoningrotary motion definitiontensile stress definition physicsmiles vs nautical mileswhat is the chemical formula of methanolorthopnoea definitionwhy is history open to ongoing and changing interpretationshow to calculate least count of vernierneoclassical writingwhat is the difference between tone and pitchdifference of alligator and crocodilemolecular formula ribosemam sir spellingparamagnetic and diamagneticenunciate vs pronouncedefine accusativedifference between amid and amidstdifference between workshop and seminardifference between altruism and prosocial behaviorwhat is intensive pronoun with examplesdifference between transgender and bisexualcations and anions definitiondifferentiate between balance of trade and balance of paymentdifference between valence electrons and valencywhat is the difference between raw and pure honeywhat is a dynamic character in literaturedifference between infrasound and ultrasoundis baking soda and bicarb soda the samemeaning of tiranga coloursatmosphere definition literarysinus cavity cysts and polypshomonym for mainwhat is the difference between a bistro and a restaurantisopropyl chemical formula