What is the resistivity of graphite?

Question

I've got 9.6*10*-3, i've been dividing the area of a piece of graphite by the gradient of the graph- if 9.6*10*-3 isnt right then how do you work out the resitivity of graphite?

I plotted the graph using length and resistance

Answer 1

You haven't told us what the graph was that you plotted!

Are you sure that you worked out the area in square metres?
What about the length of the block?

Answer 2

rho = R (A/L)

R = resistance in ohms
A = cross-sectional area in meters^2
L = length in meters

Resistivity is the resistance of a wire multiplied by the cross-sectional area of the wire divided by the length of the wire. Resistivity is a property of the material independent of the geometry of the wire. Its units are ohm-meters.

For graphite typical values are 7.837 x 10^-6 ohm-meters
http://www.ndt-ed.org/GeneralResources/MaterialProperties/ET/ET_matlprop_Misc_Matls.htm

It is orientation dependent 9.8 to 41 x 10^-6 ohm-meters for perpendicular to c-axis or parallel to c-axis
http://www.phy.mtu.edu/~jaszczak/graphprop.html

A graph of resistance on the Y-axis and length on the X-axis will have a slope (R/L). That slope should be multiplied by the cross-sectional area A of the graphite to get the resistivity rho.

Resistivity is the inverse of conductivity sigma.

Answer 3

Resistivity = Resistance x Length / Cross Sectional Area

What have you plotted on your graph ??
(i.e. what is on the y-axis and what is on the x-axis) - then I can help you out.....