Assertion : The e.m.f. of the drivercell in the potentiometer experiment should be greater than the e.m.f. of the cell to determined. reason ; the fall of potential across the potentiometer wire should not be less than the emf of the cell to be determined.

Options

A. Statement `1` is true, Statement `2`is True , Statement `2` is correct explanation for Statement `1`.
B. Statement `1` is True, Statement `2` is True, Statement `2` is NOT a correct explantion for Statement `1`.
C. Statement `1` is True, Statement `2` is False.
D. Statement `1` is False, Satement `2` is True.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided in the context of the potentiometer experiment.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
The assertion states that the e.m.f. (electromotive force) of the driver cell in the potentiometer experiment should be greater than the e.m.f. of the cell to be determined. This means if we denote the e.m.f. of the driver cell as \( E_2 \) and the e.m.f. of the cell to be determined as \( E_1 \), then the assertion can be mathematically represented as:
\[ E_2 > E_1 \]

2. **Understanding the Reason**:
The reason states that the potential drop across the potentiometer wire should not be less than the e.m.f. of the cell to be determined. This implies that for a proper measurement, the potential difference across the potentiometer wire (which is proportional to the length of the wire used) must be sufficient to balance the e.m.f. of the cell \( E_1 \). Therefore, we can express this as:
\[ V_{drop} \geq E_1 \]

3. **Analyzing the Potentiometer Setup**:
In a typical potentiometer setup, we have a long wire (AB) and a jockey that can slide along this wire. When a steady current flows through the wire, the potential drop across any length of the wire is proportional to that length. When we find a point (balancing point) where the galvanometer shows zero deflection, it indicates that the potential drop across that length of wire is equal to the e.m.f. of the cell being measured.

4. **Relating the Assertion and Reason**:
If \( E_2 \) (the e.m.f. of the driver cell) is not greater than \( E_1 \), then the potential drop across the wire will not be sufficient to measure \( E_1 \). Thus, to achieve a balancing point, we must have:
\[ E_2 > E_1 \]
This confirms that both the assertion and the reason are correct.

5. **Conclusion**:
Both the assertion and reason are true, and the reason provided is a correct explanation of the assertion. Therefore, the answer is that both the assertion and reason are true, and the reason correctly explains the assertion.