The substance which possesses zero resistance at zero K temperature is called a:

Options

A. Conductor
B. Super conductor
C. Insulator
D. Semiconductor

Answer

To solve the question "The substance which possesses zero resistance at zero K temperature is called a:", we need to analyze the properties of different types of materials and understand the concept of zero resistance.

### Step-by-Step Solution:

1. **Understanding Zero Resistance**:
- Zero resistance refers to a phenomenon where a material can conduct electricity without any opposition. This means that when an electric current flows through the material, there is no loss of energy in the form of heat.

**Hint**: Think about materials that can conduct electricity without losing energy.

2. **Identifying the Phenomenon**:
- This phenomenon of zero resistance typically occurs in certain materials at very low temperatures, close to absolute zero (0 Kelvin).

**Hint**: Consider the temperature at which materials behave differently in terms of electrical conductivity.

3. **Defining Superconductors**:
- Materials that exhibit zero resistance at low temperatures are known as superconductors. When cooled below a specific temperature known as the critical temperature (Tc), these materials allow electric current to flow without any resistance.

**Hint**: Recall the term used for materials that can conduct electricity without resistance at low temperatures.

4. **Evaluating Other Options**:
- **Conductors**: These materials have resistance that increases with temperature due to increased collisions between free electrons.
- **Insulators**: These do not conduct electricity well and typically have high resistance, which may decrease with increasing temperature.
- **Semiconductors**: Their resistance decreases with increasing temperature, but they do not achieve zero resistance at 0 K.

**Hint**: Compare the behavior of conductors, insulators, and semiconductors with superconductors regarding their resistance at different temperatures.

5. **Conclusion**:
- Based on the properties discussed, the correct answer to the question is that the substance which possesses zero resistance at zero Kelvin temperature is called a **superconductor**.

**Final Answer**: Superconductor