Question

Write the SI unit of cell constant.

Hint:

Always distinguish between common units ($cm^{-1}$) and SI units ($m^{-1}$) in competitive exams.

Answer 1

Step 1: Understanding the Concept:
The cell constant ($G^*$) of a conductivity cell is defined as the ratio of the distance between the electrodes ($l$) to the area of cross-section of the electrodes ($a$).
Step 2: Key Formula or Approach:
\[ G^* = \frac{l}{a} \]
Step 3: Detailed Explanation:
In the SI system:
The unit of length ($l$) is meters ($m$).
The unit of area ($a$) is square meters ($m^2$).
Substituting into the formula:
\[ \text{Unit of } G^* = \frac{m}{m^2} = m^{-1} \]
(Note: $cm^{-1}$ is frequently used in laboratories, but $m^{-1}$ is the standard SI unit).
Step 4: Final Answer:
The SI unit of cell constant is \( m^{-1} \).