### 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 · m2

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 · m2. For example, some vibrating sample magnetometers (VSM) use this unit.

#### 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 · m2 = 1 Ω · C = 1 H · A = 1 J/A = 1 (kg · m2 )/( s2 · A) = 1 · 108 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 · s2) = 1 N/(A · m) = 1 (V · s)/m2 = 1 J/ (A · m2) = 1 (H ·A)/ m2 = 1 Wb/m2 = 1 kg/(C · s) = 1 (N · s)/(C · m)

in vacuum B = μ0 · H