The unit of electric potential or electromotive force is the
volt
ohm
ampere
franklin

VOLT is the unit of electric potential or electromotive force. The term volt is used to honour an Italian physicist who invented the voltaic pile, Alessandro Volta.  

Volt is a measure of electric potential. Electric potential, a type  of potential energy that could be released if electric current is allowed to flow.  

Its formulas would be:  
V = potential energy / charge
V = N * m / coulomb
V = kg * m * m / s² * A * s = kg * m² / A * s³
V = A * Ω
V = W / A
V = J / C
V = eV / e  

ohm (Ω) is the unit of electrical resistance.  
ampere (A) is the unit for measuring the strength of an electric current  
watt (W) is the unit of electrical power