Low-Conductivity Material Properties Explained

Understanding the properties of materials is crucial in physics and electrical engineering. This question focuses on identifying the correct characteristic of a material that exhibits low conductivity.

Conductivity and Resistivity Relationship

Electrical conductivity, denoted by the Greek letter sigma ($\sigma$), measures how well a material conducts electric current. Conversely, electrical resistivity, denoted by the Greek letter rho ($\rho$), measures how strongly a material opposes the flow of electric current. These two properties are inversely related, defined by the equation:

$$ \sigma = \frac{1}{\rho} $$

This formula highlights that if a material has high conductivity ($\sigma$), it must have low resistivity ($\rho$), and vice versa. A material with low conductivity struggles to allow electric charge to flow through it.

Analyzing the Options

Let's examine each option in the context of a low-conductivity material:

• Option 1: High conducting material - This is incorrect. Low-conductivity is the direct opposite of being a high conducting material.
• Option 2: High resistivity - This is correct. According to the inverse relationship ($ \sigma = 1/\rho $), if a material has low conductivity ($\sigma$), it must possess high resistivity ($\rho$). Materials like rubber or glass are examples of low-conductivity materials with high resistivity.
• Option 3: Low resistance - This is incorrect. Resistance ($R$) depends not only on the material's resistivity ($\rho$) but also on its physical dimensions, specifically its length ($L$) and cross-sectional area ($A$), according to the formula $ R = \frac{\rho L}{A} $. While high resistivity often leads to higher resistance for a given shape, "low-conductivity" fundamentally describes the intrinsic material property (resistivity), not the resistance of a specific object. A very short or thick piece of a high-resistivity material could potentially have low resistance.
• Option 4: Low resistivity - This is incorrect. Low resistivity directly implies high conductivity, which contradicts the condition given in the question.

Conclusion

Based on the fundamental relationship between conductivity and resistivity, a low-conductivity conducting material is characterized by high resistivity.