A typical cell membrane is 8.0 nm thick and has an electrical resistivity of 1.3 107 Ohms · m.


(a) If the potential difference between the inner and outer surfaces of a cell membrane is 80 mV, how much current flows through a square area of membrane 1.2 µm on a side?

_____________A


(b) Suppose the thickness of the membrane is doubled, but the resistivity and potential difference remain the same. Does the current increase or decrease or remain the same?

By what factor?