4. The quantity of liquid (such as cryogenic liquid nitrogen) available in its storage tank is often monitored by a capacitive level sensor. This sensor is a vertically aligned cylindrical capacitor with outer and inner conductor radii Ra and R, whose length & spans the height of the tank. When a nonconducting liquid fills the tank to a height h from the tank's bottom, the dielectric in the lower and upper region between the cylindrical conductors is the liquid Kliq and its vapor Ky, respectively. Determine a formula for the fraction F of the tank filled by liquid in terms of the level-sensor capacitance C. h Rb Kv Kliq