Question

Which expression connects the permittivity of a dielectric medium to the capacitance of a full-slab parallel plate capacitor?

Options

• \[\varepsilon=\varepsilon_0-K\quad\text{and}\quad C=\frac{d}{\varepsilon A}\]

• \[\varepsilon=K\varepsilon_0\quad\text{and}\quad C=\frac{\varepsilon A}{d}\]

• \[\varepsilon=\frac{\varepsilon_0}{K}\quad\text{and}\quad C=\frac{\varepsilon d}{A}\]

• \[\varepsilon=K+\varepsilon_0\quad\text{and}\quad C=\frac{\varepsilon A}{K d}\]

Answer 1

The medium’s permittivity is \[\varepsilon=K\varepsilon_0\]. Substituting it into the parallel plate expression gives \[C=\varepsilon A/d\].