(a) Find the capacitance of the membrane. ( )nF If the potential difference acro

Question

(a) Find the capacitance of the membrane.

(  )nF

If the potential difference across the membrane is 85 mV, find
(b) the charge on each side of the membrane,

(  )nC

and
(c) the electric field through the membrane.

V/m

The membrane of the axon of a nerve cell is a thin cylindrical shell of radius r = 10-5 m, length L = 0.41 m, and thickness d = 10-8 m. The membrane has a positive charge on one side and a negative charge on the other, and acts as a parallel-plate capacitor of area A = 2 pi rL and separation d. Its dielectric constant is = 7. Find the capacitance of the membrane. ( )nF If the potential difference across the membrane is 85 mV, find the charge on each side of the membrane,( )nC and the electric field through the membrane.V/m

Explanation / Answer

the axon effectively behaves as a cylindrrical capacitor.

a)hence capacitace= 2pi*k*eo*L/ln(b/a)

=(1/(2*9*10^9))*7*0.41/(ln((10^-5+10^-8)/10^-5))

=1.59*10^-7 F

=159.5 nF

b)charge=CV

=13.515 nC

c)electric field=V/d

=85*10^-3/10^-8

=85*10^5 V/m

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

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