A level physics Capacitance question (3)

Can someone please explain how to do part b because I don't get where the markscheme ( the workings written in green) got the numbers from

(edited 1 month ago)

Reply 1

Eimmanuel

Study Forum Helper

Original post by 1234kelly

Can someone please explain how to do part b because I don't get where the markscheme ( the workings written in green) got the numbers from

You should have the formula in your text or note:

C_0 = \epsilon_0 \dfrac{A}{d}

----- Eq 1
which describes the capacitance C₀ of the 'empty' parallel plates,
where
A is the surface area of the plates and
d is the perpendicular distance between the plates.

Next, if a dielectric of relative permittivity ϵ_r is inserted between the plates, the new capacitance C is