What is thermal conductivity of an ideal heat insulator?

Explanation:

Heat insulators:

• A thermal insulator or insulators of heat prevents thermal energy from passing through them. e.g. plastic, rubber.
• The thermal conductivity of an ideal heat insulator is zero.
• Thermal insulation is the process of insulating material from transferring heat between the materials that are in thermal contact.
• Thermal insulation is measured by its thermal conductivity.
• Low thermal-conductive materials are used for thermal insulation.

Thermal conductivity:

• Thermal conductivity refers to the ability of a given material to conduct/transfer heat.
• It is generally denoted by the symbol ‘k’
• The reciprocal of this quantity is known as thermal resistivity.
• Materials with high thermal conductivity are used in heat sinks whereas materials with low values of ‘k’ are used as thermal insulators.
• Fourier’s law of thermal conduction (also known as the law of heat conduction) states that the rate at which heat is transferred through a material is proportional to the negative of the temperature gradient and is also proportional to the area through which the heat flows.
• The differential form of this law can be expressed through the following equation:

q = -k × ∇T
Where ∇T refers to the temperature gradient, q denotes the thermal flux or heat flux, and k refers to the thermal conductivity of the material