1. What is the conductance of device consisting of two concentric metal shells, the inner one having a radius of 20 cm, and the outer one having a radius of 40 cm, when the volume between the two shells is filled with tap water having a conductivity of 200 µS/m? (a) For a 1 volt difference between the two shells, what is the electrical current? (b) What is the current density J at a radius slightly greater than 20 cm? What is the current density at a radius just shy of 40 cm?

1. What is the conductance of device consisting of two concentric metal shells, the inner one having a radius of 20 cm, and the outer one having a radius of 40 cm, when the volume between the two shells is filled with tap water having a conductivity of 200 µS/m? (a) For a 1 volt difference between the two shells, what is the electrical current? (b) What is the current density J at a radius slightly greater than 20 cm? What is the current density at a radius just shy of 40 cm?