Assertion: In the electric field `E=(4hati+4hatj)N//C` electric potential at A (4m, 0) is more than the electric portential at `B(0,4m)`
Reason: Electric lines of forces always travel from higher potential to lower potential.

Options

A. If both Assertion and Reason are true but Reason is the correct explanation of Assertion.
B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C. If Assertion is true, but the Reason is false.
D. If Assertion is false but the Reason is true.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Electric Field
The electric field is given as:
\[ \vec{E} = 4 \hat{i} + 4 \hat{j} \, \text{N/C} \]

### Step 2: Identify Points A and B
The coordinates of the points are:
- Point A: \( (4 \, \text{m}, 0) \)
- Point B: \( (0, 4 \, \text{m}) \)

### Step 3: Calculate the Potential Difference
The potential difference between two points in an electric field can be calculated using the formula:
\[ V_A - V_B = -\vec{E} \cdot (\vec{r_A} - \vec{r_B}) \]
Where \( \vec{r_A} \) and \( \vec{r_B} \) are the position vectors of points A and B, respectively.

### Step 4: Write Position Vectors
The position vectors for points A and B are:
- \( \vec{r_A} = 4 \hat{i} + 0 \hat{j} \)
- \( \vec{r_B} = 0 \hat{i} + 4 \hat{j} \)

### Step 5: Calculate the Difference in Position Vectors
Now, calculate \( \vec{r_A} - \vec{r_B} \):
\[ \vec{r_A} - \vec{r_B} = (4 \hat{i} + 0 \hat{j}) - (0 \hat{i} + 4 \hat{j}) = 4 \hat{i} - 4 \hat{j} \]

### Step 6: Calculate the Dot Product
Next, calculate the dot product \( \vec{E} \cdot (\vec{r_A} - \vec{r_B}) \):
\[ \vec{E} \cdot (\vec{r_A} - \vec{r_B}) = (4 \hat{i} + 4 \hat{j}) \cdot (4 \hat{i} - 4 \hat{j}) \]
\[ = 4 \times 4 + 4 \times (-4) = 16 - 16 = 0 \]

### Step 7: Determine the Potential Difference
Using the result from the dot product:
\[ V_A - V_B = -0 = 0 \]
This means that the potentials at points A and B are equal:
\[ V_A = V_B \]

### Step 8: Analyze the Assertion and Reason
- **Assertion**: The electric potential at A is more than at B. (This is **false** since \( V_A = V_B \))
- **Reason**: Electric lines of force always travel from higher potential to lower potential. (This is **true**)

### Conclusion
The assertion is false, while the reason is true. Therefore, the correct answer is that the assertion is incorrect, but the reason is correct.