The dielectric constant of a metal is

Options

A. zero
B. one
C. k
D. `infty`

Answer

**Step-by-Step Solution:**

1. **Understanding Dielectric Constant**: The dielectric constant (also known as relative permittivity) is a measure of a material's ability to store electrical energy in an electric field. It is denoted by the symbol \( K \).

2. **Dielectric Constant of Metals**: For metals, the dielectric constant is considered to be infinite. This is because metals are good conductors of electricity, and when an external electric field is applied, the free charges within the metal rearrange themselves in such a way that they completely cancel the electric field inside the metal.

3. **Electric Field Inside a Metal**: In a perfect conductor (ideal metal), the electric field inside the material is zero when in electrostatic equilibrium. This means that any applied electric field does not penetrate the metal; instead, it induces surface charges that create an opposing electric field.

4. **Conclusion**: Since the electric field inside a metal is zero, the dielectric constant \( K \) is effectively infinite. Therefore, when asked about the dielectric constant of a metal, the answer is that it is infinite.

5. **Final Answer**: The dielectric constant of a metal is \( \infty \).

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