# How can the strength of an electric field be quantified?

$E = \frac{V}{d} = \frac{F}{Q} _ 2 = \frac{k {Q}_{1}}{r} ^ 2$, where:
• $E$ = Electric field strength ($N {C}^{-} 1 \mathmr{and} V {m}^{-} 1$)
• $V$ = electric potential
• $d$ = distance from the point charge ($m$)
• $F$ = Electrostatic force ($N$)
• ${Q}_{1} \mathmr{and} {Q}_{2}$ = charge on objects $1$ and $2$ ($C$)
• $r$ = distance from point charge ($m$)
• $k$ = $\frac{1}{4 \pi {\epsilon}_{0}} = 8.99 \cdot {10}^{9} N {m}^{2} {C}^{-} 2$
• ${\epsilon}_{0}$ = permittivity of free space ($8.85 \cdot {10}^{-} 12$ $F {m}^{-} 1$)