What is the electric potential V(r, theta) inside the solid dielectric sphere placed in dielectric liquid

What are the theoretical properties of a gas at a temperature of 0 kelvin?

Hen a gfci receptacle device is installed on a 20-ampere branch circuit (12 awg copper), what is the minimum volume allowance (in cubic inches) required for conductor fill for each conductor in the outlet box?

What’s #16 asking and how do i solve it?