CTET 2 Social and Science Jan 2021 Paper

The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about $500\mathrm{km}$ above the Earth's surface is called the exosphere.
Mesosphere lies above the stratosphere. It extends upward to a height of about $85\mathrm{km}$ above the Earth. Most meteors burn up in the mesosphere. Here the temperature decreases with height, reaching a minimum of about $90°\mathrm{C}$ at the mesopause (boundary between the mesosphere and the thermosphere) which makes it the coldest place on the Earth.