In the figure two parallel-plate capacitors A and B are connected in parallel across a 850 V battery. Each plate has area 57.0 cm^2; the plate separations are 3.30 mm. Capacitor A is filled with air; capacitor B is filled with a dielectric of dielectric constant κ = 3.80. Find the magnitude of the electric field within (a) the dielectric of capacitor B and (b) the air of capacitor A. What are the free charge densities σ on the higher-potential plate of (c) capacitor A and (d) capacitor B? (e) What is the induced charge density σ' on the top surface of the dielectric? Figure:
https://imgur.com/a/ryScOUp