Two parallel equipotential surfaces are apart

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Two parallel equipotential surfaces are

3.0\,\text{cm}

apart. The potential on the surface closer to a reference point is

180\,\text{V}

, and on the other surface it is

120\,\text{V}

. What is the magnitude of the average electric field between the two surfaces? (a)

3.0 \times 10^{3}\,\text{V\,m}^{-1}

(b)

6.0 \times 10^{3}\,\text{V\,m}^{-1}

(c)

2.0 \times 10^{3}\,\text{V\,m}^{-1}

(d)

2.0 \times 10^{2}\,\text{V\,m}^{-1}