Statement I: Voltmeter always gives emf of a cell if it is connected across the terminals of a cell.
Statement II: Terminal potential of a cell is given by `V= E - ir`.

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 analyze the statements given in the question, we will evaluate each statement separately and determine their validity based on the principles of electrical measuring instruments.

### Step-by-Step Solution:

1. **Understanding Statement I**:
- The statement claims that a voltmeter always gives the EMF (Electromotive Force) of a cell when connected across its terminals.
- The EMF of a cell is defined as the maximum potential difference when no current is flowing (open circuit condition).

2. **Analyzing the Circuit**:
- When a voltmeter is connected across a cell, it measures the potential difference between the terminals of the cell.
- If the voltmeter has a very high resistance (ideally infinite), it will draw negligible current from the circuit. In this case, the voltmeter will read the EMF of the cell because there is no significant voltage drop across the internal resistance of the cell.

3. **Considering Current Flow**:
- If there is a current flowing through the circuit (when the cell is connected to an external load), the potential difference measured by the voltmeter will be affected by the internal resistance of the cell.
- The terminal potential (V) can be expressed as:
\[ V = E - I \cdot r \]
where \(E\) is the EMF, \(I\) is the current flowing, and \(r\) is the internal resistance of the cell.

4. **Conclusion for Statement I**:
- Since the voltmeter does not always read the EMF (it reads \(E - I \cdot r\) when current flows), Statement I is **false**.

5. **Understanding Statement II**:
- This statement correctly states that the terminal potential of a cell is given by the equation \(V = E - I \cdot r\).
- This equation is derived from the definition of EMF and accounts for the voltage drop across the internal resistance when current flows.

6. **Conclusion for Statement II**:
- Since the equation accurately describes the relationship between EMF, terminal potential, and internal resistance, Statement II is **true**.

### Final Evaluation:
- **Statement I**: False
- **Statement II**: True

### Answer:
- The correct answer is that Statement I is false and Statement II is true.