Question

On a cold day when a room temperature is\[{{15}^{0}}C\], the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of\[{{15}^{0}}C\], because –
A) Metals have higher thermal capacity than plastics.
B) Plastics have a lower density than metals.
C) Metals are a good conductor of heat.
D) Plastics have a higher thermal conductivity than metals.

Answer 1

Hint: The relation between the temperature of the surroundings and the material property has a role to play in feeling being colder than another material kept in the same temperature. We need to understand the metallic properties related to heat.

Complete step by step solution:
We are given that a metallic piece of cap is felt to be colder than the plastic body at the same temperature on a cold day. The metals are very good conductors of heat. It can absorb the heat from the surroundings very quickly making it feel to be colder. When we touch a metallic piece, the heat conducts from our body to the metal very quickly lowering our body temperature.
The thermal capacity of a material is the energy required to rise the temperature of the material by one degree Celsius. It doesn’t affect the conduction of the material or the cold feel due to conduction in a metal in this case.
This lowering of body temperature is felt as the cold sensation to our senses when touching a metal. This is due to high thermal conductivity of the metals which is their characteristics property.

The correct answer is option C.

Note:
The cold feel on the metal pieces should not be confused with the metal being a bad conductor of heat. The metals are very good conductors of heat and they allow transfer of heat from one end to another by the method of conduction which plastics resist.