Question

Why is a thermocol lined box used as a cold storage?
A. Thermocol is a bad conductor
B. It is cheaper
C. It is easier to construct
D. None of these

Answer 1

Hint-Thermocol is made by heating the polystyrene beads within a mould. The beads expand and fuse together because of the heat provided. These expanded fused beads are made of 95 percentage air and leaves space between each other.
The presence of this large amount of air makes them a good insulator. It will not conduct heat through it.

Step by step solution:
Thermocol which is also known as expanded polystyrene is made of polystyrene. Polystyrene is a hydrocarbon polymer which is produced synthetically.
Thermocol is made by heating the polystyrene beads within a mould. The beads expand and fuse together because of the heat provided. These expanded fused beads are made of 95 percentage air and leaves space between each other.
The presence of this large amount of air makes them a good insulator. It will not conduct heat through it. So thermocol is a bad conductor of heat and hence if ice cubes are placed inside a thermocol box, it will remain in its solid form. The thermocol will prevent the coldness of the ice from getting away into the surroundings and heat from the surrounding to get into the inside of the box.
Since thermocol is a bad conductor of heat it is also used as false ceilings in order to prevent excess heat from reaching inside.

So, the correct answer is option A

Note: Thermocol is often confused with Styrofoam which is also made from polystyrene. Styrofoam is extruded polystyrene whereas thermocol is expanded polystyrene. Styrofoam is a better heat insulator than thermocol because of its closed wall structure.