An air-filled spherical capacitor is constructed with concentric spherical conducting shells; inner and other shells of radii ri = 7.00 cm and ro = 14.0 cm, respectively. (a)Use Gauss’s law to determine the electric field at a point r between the two shells (ri < r < ro). Assume that the charge on the inner shell is +Q and on the outer shell is –Q. (3pts) (b)Determine an expression for the potential difference, Vro-Vri, between the two spherical shells. (3pts) (c)Calculate the capacitance of this capacitor. (4pts)