Is a volt an SI base unit?

Answer 1

No the SI base units are:

• metre for length
• kilogram for mass
• second for time
• ampere for electric current
• kelvin for temperature
• candela for luminous intensity
• mole for the amount of substance.

Voltage is derived from the base units, metre, kilogram, seconds and ampere.

V = m2·kg·s−3·A−1

Definition of voltage

The voltage between two ends of a path is the total energy required to move a small electric charge along that path, divided by the magnitude of the charge.

V = J/C

where:

J=m2·kg·s−2

C=s·A

V = (m2·kg·s−2)/(s·A)

Thus:

V = m2·kg·s−3·A−1

For more information look at the subject of "SI derived units"