Assertion : When cells are connected in parallel to the external load, the effective emf increases
reason: All the cell will be sending the current to the external load in the same direction

Options

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

Answer

To solve the question regarding the assertion and reason about cells connected in parallel, we need to analyze both statements carefully.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that when cells are connected in parallel to an external load, the effective emf increases.
- In parallel connections, the voltage across each cell remains the same as the voltage across the load. Therefore, the effective emf does not increase; it remains equal to the emf of the individual cells if they are identical.

2. **Understanding the Reason**:
- The reason states that all the cells will be sending current to the external load in the same direction.
- This statement is true. In a parallel connection, all cells contribute to the current flowing through the external load in the same direction.

3. **Analyzing the Effective EMF**:
- The effective emf (E_eff) in a parallel connection can be calculated using the formula:
\[ E_{eff} = \frac{E_1 R_2 + E_2 R_1}{R_1 + R_2} \]
- If the cells have different emfs and internal resistances, the effective emf will be a weighted average, which will not necessarily be greater than the individual emfs.

4. **Conclusion**:
- Since the assertion is incorrect (the effective emf does not increase when cells are connected in parallel), and the reason is correct (cells do send current in the same direction), we conclude that the assertion is false, but the reason is true.

### Final Answer:
- The assertion is **false** and the reason is **true**.