Which application commonly uses mineral insulating materials due to their mechanical strength and electrical insulating properties?

The correct answer is 4) Electrical insulators for high-voltage transmission lines.

Concept:

• High Mechanical Strength: High-voltage transmission lines require insulators that can support the weight of the conductors and withstand strong winds, ice loads, and other mechanical stresses. Mineral insulators like porcelain and glass possess excellent mechanical strength.
• Electrical Insulating Properties: These materials have high dielectric strength, meaning they can withstand very high voltages without allowing current leakage or breakdown. This is crucial for preventing short circuits and ensuring the safe and efficient transmission of power.

Additional Information

• Batteries and electrodes: While some minerals are used in batteries, they are chosen for their electrochemical properties rather than their bulk mechanical strength and electrical insulation. Insulation within batteries uses different materials.
• Electrical wires for household use: The insulation on household wires is typically made of polymers (plastics or rubber) which offer flexibility and adequate insulation for lower voltages. While some mineral-insulated cables exist for specialized applications (like fire survival circuits), they are not the typical choice for general household wiring.
• Low-voltage electronic devices: Low-voltage electronics often use plastic or ceramic materials for insulation due to their ease of manufacturing and suitability for smaller components. The high mechanical strength of mineral insulators is usually not a primary requirement in these applications.