Potential difference across the terminals of a cell was measured (in volts) against different current (in ampere) flowing through the cell. A graph was drawn, which was a straight line ABC. Using the data given in the graph determine a. the emf, and
b. the internal resistance of the cell.

Explanation

To solve the problem, we will follow the steps outlined in the video transcript. We will determine the electromotive force (emf) and the internal resistance of the cell using the relationship between potential difference (V), emf (E), and internal resistance (r).

### Step-by-step Solution:

1. **Understanding the Relationship**:
The relationship between the potential difference (V), emf (E), and internal resistance (r) is given by the formula:
\[
V = E - I \cdot r
...