Which of the following statements is/are not true regarding a conductor?

Options

A. The surface of any charged conductor is an equipotential surface.
B. when a conductor is earthed, charge always flows from conductor to earth.
C. Electrostatic field inside te conductor is zero.
D. Electrostatic potential throughout the volume of conductor is constant.

Answer

To determine which of the statements regarding a conductor are not true, let's analyze each statement step by step.

### Step 1: Analyze the Statements
1. **Statement 1**: The surface of any charged conductor is an equipotential surface.
- **Explanation**: This statement is true. In electrostatics, the surface of a charged conductor is indeed an equipotential surface because the electric potential is constant across the surface.

2. **Statement 2**: When a conductor is earthed, charge always flows from the conductor to the earth.
- **Explanation**: This statement is not true. When a conductor is earthed, the flow of charge can occur in both directions. If the conductor is positively charged, electrons will flow from the earth to the conductor. If it is negatively charged, electrons will flow from the conductor to the earth. Therefore, this statement is incorrect.

3. **Statement 3**: The electric field inside the conductor is zero.
- **Explanation**: This statement is true. In electrostatic equilibrium, the electric field inside a conductor is zero. This is a fundamental property of conductors.

4. **Statement 4**: Electrostatic potential throughout the volume of the conductor is constant.
- **Explanation**: This statement is true. Since the electric field inside the conductor is zero, the potential must be constant throughout the volume of the conductor.

### Step 2: Conclusion
From the analysis, we find that:
- Statement 1: True
- Statement 2: Not True
- Statement 3: True
- Statement 4: True

Thus, the statement that is not true regarding a conductor is **Statement 2**: "When a conductor is earthed, charge always flows from the conductor to the earth."