How much energy is stored by the electric field between two square plates, 6.1 cm on a side, separated by a 3.5 mm air gap? the charges on the plates are equal and opposite and of magnitude 530 μc. express your answer using two significant figures

Explanation:

The electric field between two plates is:

Where sigma is the superficial charge density and epsilon is the permittivity of air (is about the same as vaccum)

Using the formula to determine the electric field.

The energy inside the plates is given by the energy density due to electric Field times the volume:

The volume is equal to the area of the plates times the distance between them:

resonant frequency