**1. The problem statement, all variables and given/known data**

*A parallel-plate capacitor consists of two square plates, size L x L, separated by distance d. The plates are given charge +-Q . Each part changes only one quantity; the other quantities have their initial values.*

Part A

What is the ratio E(final)/E(initial) of the final to initial electric field strengths if Q is doubled?

Part A

What is the ratio E(final)/E(initial) of the final to initial electric field strengths if Q is doubled?

**2. Relevant equations**

I know that:E = kQ/r^2 ,where k= 8.99*10^9

**3. The attempt at a solution**

I am not sure where to start here for this question.

Since it is a ratio of E final / E initial would Q cause E to be something like this?

E = k(2Q)/r^2 => 1/2E for E final?