Assertion: Electric field is aways directed perpendicular to an equipotential surface.
Reason: Equipotential surface is a surface on which at each point potential is same.

Options

A. Statement I is true, Statement II is True, Statement II is a correct explanation for statement I.
B. Statement I is true, Statement II is True, Statement II is Not a correct explanation for statement I.
C. Statement I is True, Statement II is False.
D. Statement I is False, Statement II is True.

Explanation

To solve the question, we need to analyze the assertion and the reason given in the problem.

### Step 1: Understand the Assertion
The assertion states that "Electric field is always directed perpendicular to an equipotential surface." This is a fundamental concept in electrostatics. An equipotential surface is defined as a surface where the electric potential is the same at every point.

**Hint:** Recall that electric field lines represent the direction of the force on a positive charge, and they cannot cross equipotential surfaces.

### Step 2: Understand the Reason
The reason states that "Equipotential surface is a surface on which at each point potential is the same." This is true and aligns with the definition of equipotential surfaces.

**Hint:** Remember that if the potential is the same, there can be no work done in moving a charge along the surface.

### Step 3: Analyze the Relationship
To understand why the electric field is perpendicular to the equipotential surface, consider the relationship between electric field (E) and electric potential (V). The electric field is defined as the negative gradient of the electric potential:
\[ E = -\nabla V \]
This means that the electric field points in the direction of the greatest decrease of potential. If the potential is constant (as it is on an equipotential surface), the gradient is zero, indicating that the electric field must be perpendicular to the surface.

**Hint:** Think about the implications of moving a charge along an equipotential surface. What happens to the work done?

### Step 4: Conclusion
Since the assertion is true (the electric field is indeed perpendicular to equipotential surfaces), and the reason is also true (an equipotential surface has the same potential at all points), we conclude that both statements are correct. However, the reason does not provide a direct explanation for the assertion.

**Final Answer:**
- Assertion: True
- Reason: True, but does not explain the assertion.

### Summary of the Solution
1. The assertion is true because the electric field is always perpendicular to equipotential surfaces.
2. The reason is true as it correctly defines an equipotential surface.
3. However, the reason does not explain why the assertion is true.