A capacitive level sensor shown below is used to measure a liquid level. If hmax is 135 mm, Er is 85, and the measured capacitance change is 289pF (Given that the sensor's inner plate radius r is 15 mm, the outer plate's diameter r2 is 37.5 mm). Show that: h= (C - Co) In(r2/71) 2TEn (E, - 1) What is the liquid level?