Electric field strength (2.0) (AQA A-Level Physics): Flashcards

Force per unit charge on small positive test charge

$E = \frac{F}{Q}$

Newton per coulomb ($\text{NC}^{-1}$)

Volt per metre ($\text{Vm}^{-1}$)

Yes, $1 \text{ NC}^{-1} = 1 \text{ Vm}^{-1}$

$E = \frac{Q}{4\pi\varepsilon_0 r^2}$

Decreases with square of distance ($\propto \frac{1}{r^2}$)

$E = \frac{V}{d}$

$8.85 \times 10^{-12} \text{ F m}^{-1}$

Yes, direction is that of force on positive test charge