MCQ Detailed View

Conductors are materials that allow electric current to flow through them easily due to the presence of free-moving electrons. Metals are typically good conductors because their atomic structure has loosely bound outer electrons that can move freely when a potential difference is applied. Among the options given—aluminium, gold, and graphite—all are conductors of electricity.

Aluminium (Al): A lightweight metal widely used in power transmission lines. It conducts electricity well due to the availability of free electrons and is preferred where low weight and good conductivity are required.

Gold (Au): One of the best conductors of electricity. Although expensive, gold is used in delicate electronic circuits and connectors because it does not corrode or tarnish, ensuring long-lasting, stable conductivity.

Graphite: A non-metal form of carbon arranged in layers. Each carbon atom in graphite is bonded to three others, leaving one free electron to move. This delocalized electron flow allows graphite to conduct electricity, making it unique among non-metals.

Since all three listed materials can conduct electric current efficiently, none of them are non-conductors. A non-conductor, or insulator, is a material that resists the flow of electricity. Examples of insulators include rubber, plastic, glass, and wood. These substances have tightly bound electrons, preventing electric charge from moving freely.

The option “All are conductors” is correct because:

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  Aluminium → conductor

  
  


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  Gold → conductor

  
  


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  Graphite → conductor

  
  

This question helps students understand that not only metals but also some non-metals (like graphite) can conduct electricity due to their atomic structure. The distinction between conductors and insulators is a fundamental concept in Physics, forming the basis of how electrical circuits and devices are designed.