#### Question

The two square faces of a rectangular dielectric slab (dielectric constant 4⋅0) of dimensions 20 cm × 20 cm × 1⋅0 mm are metal-coated. Find the capacitance between the coated surfaces.

#### Solution

The area of the plates of the capacitor is given by

`A = 20 "cm" xx 20 "cm" = 400 "cm"^2`

⇒ `A = 4 xx 10^-2 "m"`

The separation between the parallel plates is given by

`d = 1 "m" = 1 xx 10^-3 "m"`

Here, the thickness of the dielectric is the same as the separation between the parallel plates.

Thus, the capacitance is given by

`C = (∈_0Ak)/d = ((8.85 xx 10^-12) xx (4 xx 10^-2) xx 4)/10^-3 = 1.42 "nF"`

Is there an error in this question or solution?

Solution The Two Square Faces of a Rectangular Dielectric Slab (Dielectric Constant 4⋅0) of Dimensions 20 Cm × 20 Cm × 1⋅0 Mm Are Metal-coated. Find the Capacitance Between the Coated Surfaces. Concept: Capacitors and Capacitance.