Assertion: Terminal potential difference of a cell is always less than its emf.
Reason: Potential drop on internal resistance of cell increases terminal potential difference.

Options

A. a.If both Assertion `&` Reason are True `&` the Reason is a correct explanantion of the Assertion
B. b.If both Assertion `&` Reason True but Reason is not a correct explanation of the Assertion
C. c.If Assertion is True but the Reason is False
D. d.If both Assertion `&` Reason are False.

Answer

To analyze the assertion and reason provided in the question, we can break down the concepts step by step:

### Step 1: Understanding the Assertion
The assertion states that the terminal potential difference of a cell is always less than its EMF (Electromotive Force).

- **Explanation**: The EMF of a cell is the maximum potential difference when no current is flowing. When a current flows, some energy is lost due to the internal resistance of the cell, leading to a lower terminal voltage.

### Step 2: Analyzing the Case with No Current
In the case where no current is flowing (I = 0):

- **Terminal Voltage (V)**: When there is no current, the terminal voltage (V) is equal to the EMF (E) of the cell.
- **Conclusion**: In this scenario, V = E. Therefore, the assertion that the terminal potential difference is always less than the EMF is false in this case.

### Step 3: Analyzing the Case with Current Flowing
Now consider the case where current is flowing through the cell (I > 0):

- **Internal Resistance**: The internal resistance (r) of the cell causes a voltage drop when current flows.
- **Terminal Voltage (V)**: The relationship can be expressed as:
\[ V = E - I \cdot r \]
- **Conclusion**: Here, since \( I \cdot r \) is a positive value, it follows that \( V < E \) when current is flowing. Thus, the assertion holds true in this case.

### Step 4: Analyzing the Reason
The reason states that the potential drop on the internal resistance of the cell increases the terminal potential difference.

- **Explanation**: This is incorrect. The potential drop across the internal resistance actually decreases the terminal potential difference. The correct relationship shows that the terminal voltage decreases due to the internal resistance when current flows.

### Final Conclusion
- **Assertion**: False (it is not always less than EMF; it can be equal when no current flows).
- **Reason**: False (the potential drop decreases the terminal voltage, not increases it).

### Answer
Both the assertion and the reason are false.