Which of the following materials is a good conductor of heat? *
A glass
B plastic
C aluminium
The correct answer and explanation is :
The correct answer is C) Aluminium.
Explanation:
Heat conduction refers to the transfer of thermal energy through a material from a region of higher temperature to one of lower temperature, and this process is most efficient in materials that are good conductors of heat. Conductivity is the property that determines how well heat can pass through a material.
Aluminium, as a metal, is a good conductor of heat. It has a high thermal conductivity, which means that it allows heat to flow through it rapidly. This makes aluminium useful in applications where efficient heat transfer is necessary, such as in cookware, heat exchangers, and radiators. Its ability to conduct heat is due to the free electrons within its structure, which can move easily and transfer kinetic energy from the hotter part of the material to the cooler part.
On the other hand, glass and plastic are poor conductors of heat, making them insulators rather than conductors.
- Glass is generally a poor conductor of heat. It has a relatively low thermal conductivity compared to metals. While glass can absorb heat, it does not transfer that heat efficiently. This is why double-glazed windows, which use layers of glass, are effective in insulating homes and reducing heat transfer. The lack of free electrons in glass means that heat does not move easily through it.
- Plastic, like glass, is also a poor conductor of heat. Plastics are composed of polymers, which are large molecules that do not allow free movement of electrons. This makes them good insulators, often used in handles for cooking utensils or in electrical insulation. Plastics are often used where the goal is to prevent heat transfer rather than to facilitate it.
Thus, aluminium is the correct answer because it is a metal with high thermal conductivity, while glass and plastic are both insulators with low thermal conductivity.