# Henry (unit)

**henryhenriesHExahenryGigahenryMegahenryMillihenryPicohenryZettahenryAh**

The henry (symbol: H) is the SI derived unit of electrical inductance.wikipedia

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### Inductance

**mutual inductanceinductivemutual induction**

The henry (symbol: H) is the SI derived unit of electrical inductance. The inductance of an electric circuit is one henry when an electric current that is changing at one ampere per second results in an electromotive force of one volt across the inductor: Formulas can be used to calculate the inductance of many common arrangements of conductors, such as parallel wires, or a solenoid.

In the SI system, the unit of inductance is the henry (H), which is the amount of inductance that causes a voltage of one volt, when the current is changing at a rate of one ampere per second.

### Joseph Henry

**Henry, JosephHenryJoseph Henry Papers Project**

If a current of 1 ampere flowing through the coil produces flux linkage of 1 weber turn, the coil has a self inductance of 1 henry. The unit is named after Joseph Henry (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791–1867) in England.

The SI unit of inductance, the Henry, is named in his honor.

### SI derived unit

**derived unitderived unitsJ/kg**

The henry (symbol: H) is the SI derived unit of electrical inductance. The henry is a derived unit based on four of the seven base units of the International System of Units: kilogram (kg), metre (m), second (s), and ampere (A).

### Weber (unit)

**weberWbwebers**

If a current of 1 ampere flowing through the coil produces flux linkage of 1 weber turn, the coil has a self inductance of 1 henry. The unit is named after Joseph Henry (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791–1867) in England. :in which the following additional derived units occur: coulomb (C), farad (F), joule (J), weber (Wb), tesla (T), volt (V), hertz (Hz), and ohm .

H = henry,

### International System of Units

**SISI unitsSI unit**

The henry is a derived unit based on four of the seven base units of the International System of Units: kilogram (kg), metre (m), second (s), and ampere (A).

### Kilogram

**kgmgmilligram**

The henry is a derived unit based on four of the seven base units of the International System of Units: kilogram (kg), metre (m), second (s), and ampere (A).

Three other base units (cd, A, mol) and 17 derived units (N, Pa, J, W, C, V, F, Ω, S, Wb, T, H, kat, Gy, Sv, lm, lx) in the SI system were defined in relation to the kilogram, and thus its stability was important.

### Joule

**JkJMJ**

:in which the following additional derived units occur: coulomb (C), farad (F), joule (J), weber (Wb), tesla (T), volt (V), hertz (Hz), and ohm .

At the second International Electrical Congress, on 31 August 1889, the joule was officially adopted alongside the watt and the quadrant (later renamed to henry).

### Permeability (electromagnetism)

**permeabilitymagnetic permeabilityrelative permeability**

The inductance of a coil depends on its size, the number of turns, and the permeability of the material within and surrounding the coil.

In SI units, permeability is measured in henries per meter (H/m), or equivalently in newtons per ampere squared (N⋅A −2 ).

### Ohm

**Ωohmsmegohm**

:in which the following additional derived units occur: coulomb (C), farad (F), joule (J), weber (Wb), tesla (T), volt (V), hertz (Hz), and ohm .

in which the following units appear: volt (V), ampere (A), siemens (S), watt (W), second (s), farad (F), henry (H), joule (J), kilogram (kg), metre (m), and coulomb (C).

### Tesla (unit)

**teslaTteslas**

:in which the following additional derived units occur: coulomb (C), farad (F), joule (J), weber (Wb), tesla (T), volt (V), hertz (Hz), and ohm .

### Inductor

**inductorscoilinductive**

* Inductor

In the International System of Units (SI), the unit of inductance is the henry (H) named for 19th century American scientist Joseph Henry.

### Ampere

**AmAamp**

If a current of 1 ampere flowing through the coil produces flux linkage of 1 weber turn, the coil has a self inductance of 1 henry. The unit is named after Joseph Henry (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791–1867) in England. The henry is a derived unit based on four of the seven base units of the International System of Units: kilogram (kg), metre (m), second (s), and ampere (A). The inductance of an electric circuit is one henry when an electric current that is changing at one ampere per second results in an electromotive force of one volt across the inductor:

### Michael Faraday

**FaradayFaraday, MichaelM. Faraday**

If a current of 1 ampere flowing through the coil produces flux linkage of 1 weber turn, the coil has a self inductance of 1 henry. The unit is named after Joseph Henry (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791–1867) in England.

### Electric current

**currentelectrical currentcurrents**

The inductance of an electric circuit is one henry when an electric current that is changing at one ampere per second results in an electromotive force of one volt across the inductor:

### Second

**ssecmegasecond**

The henry is a derived unit based on four of the seven base units of the International System of Units: kilogram (kg), metre (m), second (s), and ampere (A). The inductance of an electric circuit is one henry when an electric current that is changing at one ampere per second results in an electromotive force of one volt across the inductor:

### Electromotive force

**EMFelectromotive force (EMF)ℰ**

The inductance of an electric circuit is one henry when an electric current that is changing at one ampere per second results in an electromotive force of one volt across the inductor:

### Volt

**VkVvolts**

:in which the following additional derived units occur: coulomb (C), farad (F), joule (J), weber (Wb), tesla (T), volt (V), hertz (Hz), and ohm . The inductance of an electric circuit is one henry when an electric current that is changing at one ampere per second results in an electromotive force of one volt across the inductor:

### Metre

**metermmetres**

The henry is a derived unit based on four of the seven base units of the International System of Units: kilogram (kg), metre (m), second (s), and ampere (A).

### Coulomb

**CPicoCoulomBExacoulomb**

### Farad

**microfaradFpF**

### Hertz

**MHzkHzHz**

### National Institute of Standards and Technology

**NISTNational Bureau of StandardsBureau of Standards**

The United States National Institute of Standards and Technology recommends users writing in English to use the plural as henries.

### Solenoid

**solenoidselectromechanical solenoidmagnetizing current loop**

Formulas can be used to calculate the inductance of many common arrangements of conductors, such as parallel wires, or a solenoid.

### Wire

**stranded wireInsulated wirewire products**