Question

Resistivity measurements on the leaves of corn plants are a good way to assess stress and overall health. The leaf of a corn plant has a resistance of 2.2 MΩΩ measured between two electrodes placed 20 cm apart along the leaf. The leaf has a width of 2.1 cm and is 0.20 mm thick. Part A What is the resistivity of the leaf tissue in (ΩΩ m)?

Answer 1

R = rho L / A

rho is resistivity. You are given resistance, length, and figures to compute the cross-sectional area.

Units of resistivity areΩ-meters.

rho = R A / L
rho = 2.2Mohm (2.1cm * 0.20mm) / 20cm
rho = 48 Ω m