Question

Calculate the conductance of a conduit the cross-sectional area of which is 3.0 cm2 and the length of which is 9.0 cm, given that its conductivity is 0.80 ohm-1cm-1.

Answer 1

Answer: $0.266 ohm^{-1}$

Explanation: Specific conductance or conductivity is the conductance for unit volume of a solution.

$\kappa=C\times \frac{l}{a}$

where,

$\kappa$ =Specific conductance  or Conductivity=$0.80ohm^{-1}cm^{-1}$

C = Conductance = ?

l = length= 9.0 cm

a = area = 3.0$cm^2$

$\frac{length}{area}$= cell constant =$\frac{9.0cm}{3.0cm^2}=3cm^{-1}$

$0.80ohm^{-1}cm^{-1}=C\times 3cm^{-1}$

$C=0.266 ohm^{-1}$

Answer 2

For resistance we have R=ρ l/a
 thus for conductance we have K=σ a/l
conductance,K=1/R
conductivity,σ =1/ρ

σ = .80 Ω-1 cm-1
l =9 cm
a = 3 cm²
K=.80 ×3/9
  =0.26 Ω-1