Electric fields

• Electric field strength (E):

  $E=$$Δv/Δd$

  $E=$$F/q$
• Electric field strength at a point:

  $E=$$Q/4πε0 r^2$
• Electric force between two point charges:

  $F=$$Qq/4πε0 r^2$
• Electric potential:

  $V=$$Q/4πε0 r$
• Electric potential energy :

  $EPE=$$Vq$

  $EPE=$$Qq/4πε0 r$