JEE Main & Advanced Physics Thermometry, Calorimetry & Thermal Expansion Temperature

Temperature is defined as the degree of hotness or coldness of a body. The natural flow of heat is from higher temperature to lower temperature.

Two bodies are said to be in thermal equilibrium with each other, when no heat flows from one body to the other. That is when both the bodies are at the same temperature.

(1) Temperature is one of the seven fundamental quantities with dimension \[[\theta ]\]. It is a scalar physical quantity with S.I. unit kelvin.

(2) When heat is given to a body and its state does not change, the temperature of the body rises and if heat is taken from a body its temperature falls i.e. temperature can be regarded as the effect of cause "heat".

(3) According to kinetic theory of gases, temperature (macroscopic physical quantity) is a measure of average translational kinetic energy of a molecule (microscopic physical quantity).

(4) Although the temperature of a body can to be raised without limit, it cannot be lowered without limit and theoretically limiting low temperature is taken to be zero of the kelvin scale.

(5) Highest possible temperature achieved in laboratory is about 108K while lowest possible temperature attained is \[{{10}^{-8}}K\].

(6) Temperature of the core of the sun is \[{{10}^{7}}K\] while that of its surface is 6000 K.

(7) Normal temperature of human body is 310. 15 K \[({{37}^{o}}C={{98.6}^{o}}F)\].

(8) NTP or STP implies 273.15K \[({{0}^{o}}C={{32}^{o}}F)\]