• An electric field exists in a region of space when a test charge placed at any point in the region has a force exerted upon it

The electric field is a vector denoted by $\overrightarrow\epsilon$ A test charge $q$ will experience an electric force given by $\overrightarrow F_E = q\overrightarrow\epsilon$

• The directions of the electric force and electric field are determined by a positive test charge

For a point charge $q_2$, the magnitude of the electric field at a distance $r$ from the charge is $\epsilon = \frac{kq_2}{r^2}$

• Electric field lines are continuous lines of force that show the direction of electric for at all point in the electric field around a charge or charges
• An electric field between two parallel plate of charge is uniform and perpendicular to the plates
  • The electric field outside the parallel plates is zero
• One application of electric fields is in electrostatic precipitators, which use electric fields to remove extremely small particles of soot, dust, and ash from flue gases
• Some organisms can detect the weak fields produced by the movement of other organisms