Potential difference and current

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To calculate the current flowing through a cell membrane, the resistance can be determined using the formula R = p(L/A), where p is the resistivity, L is the thickness of the membrane, and A is the area of the membrane. The thickness of the membrane is 8.0 nm, and the area for a square side of 1.3 µm is calculated as A = (1.3 µm)^2. With the potential difference of 75 mV, Ohm's law (V = IR) can be applied to find the current by rearranging to I = V/R. The discussion emphasizes the importance of correctly identifying the values for L and A to accurately compute the current. Understanding these relationships is crucial for solving the problem effectively.
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Homework Statement



A typical cell membrane is 8.0 nm thick and has an electrical resistivity of 1.3 10^7 m. If the potential difference between the inner and outer surfaces of a cell membrane is 75 mV, how much current flows through a square area of membrane 1.3 µm on a side?

Homework Equations



I was thinking to use R=p(L/A) and then V=IR to solve for the current, but I wasn't sure what to use for numbers. I know that V=75 mV and p=1.3 x 10^7, but would L=1.3 micrometers and A=L x 8.0 nm ?
 
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First find the resistance, R, by using the formula you wrote down: R=p(L/A). You know the length, L, which is like the thickness. The area, A, is also given and you know the resistivity of the specimen. Whats the problem?
 

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