Question

When a solution of specific conductance $1.342{\text{Sm}}^{-1}$ was placed in a conductivity cell with parallel electrodes, the resistance was found to be $170.5\text{ohm}$. The area of the electrodes is $1.86\times {10}^{-4}{\text{m}}^2$ . Calculate the distance between the electrodes.

• A. $0.0452\text{m}$
• B. $0.425\text{m}$
• C. $4.25\text{m}$
• D. $42.5\text{m}$

Answer 1

The correct option is A $0.0452\text{m}$

As per the equation:
$G=\frac{1}{R}$ (G is conductance ) ……… (1)
$\kappa =G\times \frac{l}{A}$ ………….. (2)
From 1 and 2 we can also write: $\kappa =\frac{1}{R}\times \frac{l}{A}$ …………. (3)
Putting the values in equation 3:
$1.342=\frac{1}{170.5}\times \frac{l}{1.86\times {10}^{-4}}$
$\therefore$ $l=1.342\times 170.5\times 1.86\times {10}^{-4}$
On solving we get;
$l=0.0425m$