10.6 Capacitors: Lab 4

The electric field between two charged parallel plates with uniformly distributed electric charge, such as in a parallel-plate capacitor, is constant in both magnitude and direction, except near the edges of the plates.

The magnitude of the electric field between two charged parallel plates, where the plate separation is much smaller than the dimensions of the plates, can be described with the equation:

$$E_c = \frac{Q}{k\varepsilon_0 A}$$

Where:

• $E_c$ = Electric field strength ($\mathrm{N/C}$)
• $Q$ = Charge on the plates ($\mathrm{C}$)
• $k$ = Dielectric constant (dimensionless)
• $\varepsilon_0$ = Permittivity of free space ($8.85 \times 10^{-12} \mathrm{C^2/N \cdot m^2}$)
• $A$ = Area of the plates ($\mathrm{m^2}$)

A charged particle between two oppositely charged parallel plates undergoes constant acceleration and therefore its motion shares characteristics with the projectile motion of an object with mass in the gravitational field near Earth's surface.