What is the difference between matter and electromagnetic waves?
admin Electromagnetic waves are very much different from the matter waves and in many ways. a) Speed of matter waves is very much less than the speed of electromagnetic waves. b)…
April 2025
Derive the Bohr angular momentum from de Broglie’s relation
Let us consider an electron revolving around a nucleus of an atom. The wave train formed by it is as shown in figure. Now, for the wave to be in…
Define third law of thermodynamics. Discuss the importance of third law of thermodynamics.
The third law of thermodynamics states that: “The entropy of all the perfect crystalline solids is zeros at absolute zero temperature”. The third law of thermodynamics is also referred to…
What is irreversible process? Give an example of irreversible process.
Irreversible process: An Irreversible process is one in which heat is transferred through a finite temperature. Irreversible process is also known as spontaneous process because these processes take place at…
Define the Nernst Heat Theorem
The Nernst Heat Theorem Let us consider the Gibbs-Helmholtz equation which includes chemical reaction i.e.: ∆G – ∆H = T (∂ (∆G)/∂T) P ………………………………….. (1) Where ∆G ——-> change in…
Determine the Absolute Entropies of Solids
Absolute entropies of solids: Entropy change for an infinitesimally small change of a state of a substance is given as: dS = dq / T If the changes take place…
Derive the Entropy of Real Gases
Entropy of real gases: We know that: (∂S / ∂P)T = – (∂V / ∂T)P ……………………. (1) is one of the Maxwell relations which can also be written as: dS…
Define Carnot Theorem and also give its proof.
Carnot theorem states that no heat engine working in a cycle between two constant temperature reservoirs can be more efficient than a reversible engine working between the same reservoirs. In…
Calculate the maximum efficiency of an engine operating between 120o C and 35o C
Maximum efficiency of an engine working between temperatures T2 and T1 is given by the fraction of the heat absorbed by an engine which can be converted into work is…
A Carnot engine converts one sixth of the heat input into work. If the sink temperature is reduced by 62o C, the efficiency gets doubled. Find the source and the sink temperature.
Maximum efficiency of an engine working between temperatures T2 and T1 is given by the fraction of the heat absorbed by an engine which can be converted into work is…