Question

Which of the following is an insulator?

• A. Copper
• B. Silver
• C. Aluminium
• D. Rubber

Hint:

Distinguish between conductors (materials that allow easy flow of electricity due to free electrons) and insulators (materials that resist the flow of electricity due to the absence of free electrons). Metals are generally good conductors, while materials like rubber, glass, and plastic are good insulators.

Answer 1

The Correct Option is D

Step 1: Understand the definition of an insulator.
An electrical insulator is a material that does not allow electric current to flow through it easily. Insulators have very high electrical resistance. Step 2: Analyze the electrical conductivity of the given materials.
Copper: Copper is a metal and a very good conductor of electricity due to the presence of free electrons. 
Silver: Silver is also a metal and an excellent conductor of electricity, even better than copper in terms of conductivity. 
Aluminium: Aluminium is another metal and a good conductor of electricity, commonly used in power transmission lines. 
Rubber: Rubber is a polymer and a poor conductor of electricity. It has very few free electrons, making it an excellent electrical insulator. 

Step 3: Identify the insulator among the given options.
Based on their electrical conductivity properties, rubber is an insulator, while copper, silver, and aluminium are conductors.