(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

You have 2 square metal plates of side length L, separated by a very small distance d. The two plates are held at fixed potential difference ΔV by a battery. A thin slab with dielectric constant κ and thickness d is inserted a distance x into the gap between the plates. (a) What is the equivalent capacitance? (b) How much energy is stored in the capacitor? (c) What is the magnitude of the electric force exerted on the dielectric slab? (d) Does this force tend to pull the slab into the gap, or to repel it from the gap? Hint: If you place two capacitors side by side and wire them so that they always have the same electric potential across them, the total capacitance is equal to the sum of the individual capacitances.

2. Relevant equations

C_{k}=kC

k=E_{vacuum}/E_{dielectric}

C=q/deltaV

3. The attempt at a solution

I'm a bit confused by what they are asking for really, if they expect us to actually get numbers out of this, I don't see how it is possible. As for part a, C_{k}=kq/deltaV

But q isn't a known constant in this situation so I don't know if this is an acceptable answer.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Dielectric question

**Physics Forums | Science Articles, Homework Help, Discussion**