Cell constant has unit `m^(-1)`.

Answer

To solve the question regarding the unit of cell constant, we can break it down step by step.

### Step-by-Step Solution:

1. **Understanding Cell Constant**:
The cell constant (denoted as \( k \)) is defined as the ratio of the distance between the two electrodes (length) to the area of cross-section of the electrodes.

2. **Formula for Cell Constant**:
The formula for cell constant can be expressed as:
\[ k = \frac{L}{A} \]
where:
- \( L \) = distance between the electrodes (length)
- \( A \) = area of cross-section of the electrodes

3. **Units of Length**:
The distance \( L \) is measured in meters (m), which is the SI unit for length.

4. **Units of Area**:
The area \( A \) is measured in square meters (m²), which is the SI unit for area.

5. **Calculating the Unit of Cell Constant**:
Now, substituting the units into the formula for cell constant:
\[ \text{Unit of } k = \frac{\text{Unit of } L}{\text{Unit of } A} = \frac{m}{m^2} \]
Simplifying this gives:
\[ \text{Unit of } k = m^{-1} \]

6. **Conclusion**:
Therefore, the unit of cell constant is indeed \( m^{-1} \), confirming that the statement given in the question is true.