Question 22 (10 pts) A coaxial cable consists of an inner conductor of radius a, an outer cylindrical conducting shell of inner radius b and outer radius c, and a material with dielectric constant K filling the region between a and b. The cable can be treated as infinitely long and straight; it is shown in cross-section. The direction out of the page is +z. a) Find the capacitance per unit length of the cable. b) If a large potential difference is placed between the inner and out conducto Adobe Acrobat I what radius will the dielectric break down first?