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Temperature  Temperature is a parameter which represents average random energy per unit molecule. As random energy per unit molecules decreases then it means that temperature will get reduce and vice-versa. For more details on temperature or difference between temperature and heat check out  Lecture - 6 . Conversion of celsius to fahrenheit scale  There there is no Rocket Science behind it you just need to remember a simple formula for this conversion and that is- T c / 100 = (T f - 32) / 180 'T c ' represents temperature in degree Celsius scale 'T f 'represents temperature in fahrenheit scale Celsius and Fahrenheit scale are based upon 2 reference points which are boiling and freezing. In Celsius scale 0 denotes the freezing point of water and 100 denotes the boiling point of water. Whereas in fahrenheit scale reading of 32 denotes freezing point of water and reading of 212 denotes boiling point of water. Conversion of celsius to kelvin scale  F...

Hey friends, this blog does not contain any sequel of my lectures. It only contains answers of those questions which people asks from me very frequently. These are basically intresting facts and natural phenomenon which we observe in our daily life. So some of them are as follows- 1) wheather Carnot efficiency is 100% efficiency or not? Most of the students are really confused with this. They consider that Carnot efficiency is always 100%, but it's not true. Actually Carnot efficiency can never be 100% for any particular system, 100% efficiency never exist, even in our theories also because concept of 100% efficiency violates Kelvin Planck statement of second law of thermodynamics. Kelvin planck states that it is impossible to construct an engine which exchange heat from only one heat source. Below is the diagram- Above shown machine is a perpetual motion machine of second kind (PMM 2), which converts all the heat into work. This machine have 100% efficiency. So remember, n...

Before continuing in zeroth law, let us understand some basic terms - Temperature is a parameter which represents average random energy per unit molecule. As random energy per unit molecules decreases then it means that temperature will get reduce and vice-versa. Heat is the form of energy which transfers from it's high to low value. It is a method of energy transfer which takes place due to difference in temperature. As heat transfer from hot body to cold body, then random energy per unit molecule start decreasing in hot body which means that temperature start decreasing in hot body and random Energy per unit molecule start increasing in cold body which means that temperature of cold body start increasing gradually. All this process occurs because of heat transfer.  Hotness or coldness is the feeling associated with heat transfer rate. This basic concept is important to understand, so now let's move zeroth law. Zeroth law of thermodynamics Zeroth law of thermodyna...

Gibbs phase rule   The Gibbs phase rule describe the possible number of degrees of freedom in a closed system at Equilibrium, in terms of number of seperate phases and the number of chemical constituents in the system. It was given by J.W Gibbs in 1870. It's formula is - P+F = C+N   or   P+F = C+2 Here,  'P' represents number of phases (liquid, gas, solid) 'C' represents number of chemical constituents 'F' represents degrees of freedom. Degrees of freedom is defined as the minimum number of independent intensive variables are required to fix the state of the system 'N' represents number of non-compositional variables  In Thermodynamics there are 2 non-compositional variables that are pressure and temperature. So value of 'N' = 2 in Thermodynamics always. For example  -  1) Calculate 'F' of gaseous mixture of oxygen and nitrogen   P = 1 because only gaseous phase is there  C = 2 because two gasses...

Macroscopic approach In this approach we consider a certain quantity of matter without taking into account the events occurring at molecular level. This comes under classical thermodynamics. The analysis of macroscopic system require simple mathematical formula. Few properties are needed to describe such a system. The values of the properties of system are there average values. For example consider a sample of gas contains in a closed cylinder. The pressure of the gas is the average value of pressure exerted by the millions of individual molecules. This approach can be applied if the continuum concept is valid. According to Continuum concept the matter is treated as continuously distributed without any void or gap present between the molecules. Continuum concept is valid if the mean free path is much less than the system dimensions. Now, mean free path is defined as the average distance travelled by a molecule between two successive collision. Microscopic approach This appro...