Q. Which material is used for heat-resistant thermal insulation?
Answer: Asbestos
Notes: Asbestos is a natural fibrous silicate mineral known for its high heat resistance and low thermal conductivity. It was widely used in boilers, furnaces, and fireproofing materials during the 20th century. Its fibers can withstand high temperatures without degrading. Due to health risks such as lung cancer and asbestosis, asbestos use is now heavily restricted or banned in many countries.