Problem 22.54 Variations in the resistivity of blood can give valuable clues to

Question

Problem 22.54

Variations in the resistivity of blood can give valuable clues to changes in the blood's viscosity and other properties. The resistivity is measured by applying a small potential difference and measuring the current. Suppose a medical device attaches electrodes into a 1.5-mm-diameter vein at two points 5.0 cm apart.

Part A

What is the blood resistivity if a 8.6V potential difference causes a 240?A current through the blood in the vein?

Problem 22.54 Variations in the resistivity of blood can give valuable clues to changes in the blood's viscosity and other properties. The resistivity is measured by applying a small potential difference and measuring the current. Suppose a medical device attaches electrodes into a 1.5-mm-diameter vein at two points 5.0 cm apart. Part A What is the blood resistivity if a 8.6V potential difference causes a 240?A current through the blood in the vein? Express your answer using two significant figures.

Explanation / Answer

Note that

V = IR

As

R = rho L/A

Then

V = I (rho) L /A

Thus,

rho = A V / [I L]

Here

A = cross section area of the vein = pi*r^2 = 1.767E-6 m^2

V = 8.6 V

I = 240E-6 A

L = 0.05 m

Thus,

rho = 1.266 ohm/m   [ANSWER]

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.