### Base units

#### Time t

second: **s** – The base unit of time in the International Systems of Units.

#### Length L

meter: **m** – The base unit of length in the International Systems of Units.

angstrom (ångström): **Å** – A metric unit of length, equal to **10 ^{-10}** m. Not that it is not part of the SI system of units, but it can be considered as part of the metric system in general.

#### Mass m

kilogram: **kg** – The base unit of mass in the International Systems of Units.

#### Electric current

ampere: **A** – The base unit of electric current in the International Systems of Units.

#### Thermodynamic temperature

kelvin: **K** – The base unit of thermodynamic temperature in the International Systems of Units.

#### Amount of substance

mole: **mol** – The base unit of amount of substance in the International Systems of Units.

#### Luminous intensity

candela: **cd**– The base unit of luminous intensity in the International Systems of Units.

### Magnetism

#### Magnetic moment m (vector)

ampere meter squared: **A · m ^{2}**

electromagnetic unit: **emu** – Note that emu is not a unit. However, it is sometimes used to describe the strength of a magnetic moment and has the value of **10 ^{-3}**

**A · m**. For example, some vibrating sample magnetometers (VSM) use this unit.

^{2}#### Magnetic field strength **H**

ampere per meter: **A/m**

#### Magnetic flux

Weber: **Wb **– The weber is a **derived **unit of the magnetic flux in the International System of Units. This unit is named in honor of **Wilhelm Eduard Weber**.

1 **Wb** = 1 **V · s** = 1 **T · m ^{2}** = 1

**Ω · C**= 1

**H · A**= 1

**J/A**= 1

**(kg · m**= 1

^{2})/( s^{2}· A)**·**

**10**

^{8}Mx#### Magnetic flux density or magnetic induction **B**

Tesla: **T** – The tesla is a **derived **unit of the magnetic induction in the International System of Units. This unit is named in honor of **Nikola Tesla**.

1 **T** = 1 **kg/(** **A · s ^{2})** = 1

**N/(A · m)**= 1

**(V · s)/m**= 1

^{2}**J/ (A · m**= 1

^{2})**(H ·A)/ m**= 1

^{2}**Wb/m**= 1

^{2}**kg/(C · s)**=

**1 (N · s)/(C · m)**

in vacuum **B** = μ_{0} · **H**