Heat

Cryogenic refers to the science and technology of producing and studying materials at very low temperatures, typically below –150°C (or about 123 K). It involves the behavior of materials and gases when cooled to extremely low temperatures.

In short:
Cryogenic = related to very low temperatures and their effects on matter.

The S.I. unit of this physical quantity is
Joule per Kelvin (J/K). C=Q/T

Cryogenics is the study of the production and behaviour of materials at extremely low temperatures (below-150 degrees Centigrade) to lift and place heavier objects in space.

Due to being a poor conductor of heat, wood does not receive any external heat, due to which the temperature of the ice does not decrease, and it melts slowly.

At hill stations, the boiling point of water will be lower than 100°C.

Reason:
At higher altitudes (like hill stations), atmospheric pressure is lower than at sea level. Since boiling point decreases with decreasing pressure, water boils at a temperature below 100°C.

In abnormal conditions (fever etc.), it increases and can sometimes go below the minimum limit (36.5°C)
Therefore, the range of the clinical thermometer is kept from 35 °C to 42 °C.

In abnormal conditions (fever etc.), it increases and can sometimes go below the minimum limit (36.5°C)
Therefore, the range of the clinical thermometer is kept from 35 °C to 42 °C.

Mercury Thermometers are based on the principle that liquids expand when heated and contract when cooled.

So, when the temperature increases the mercury expands are rises up the tube and when temperature decreases it contracts and does the opposite.
Hence option (b) will be the correct answer.