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Node id: 5166page

Find the specific heat $C_H$ of a substance at constant enthalpy and show that it is equal to
$$ C_H\,=\,\frac{C_p}{1\,-\,\frac{T}{V}\times\left(\frac{\partial V}{\partial T}\right)_p} $$
where we are using the standard notation.


AK-47's picture 22-01-13 18:01:19 n

[NOTES/EM-01011] $\vec B$ vs $\vec H$ --- Naming convention.

Node id: 5953page

We will call \(\vec B\) field as magnetic field when no medium is present.\\ In presence of a magnetic medium, \(\vec B\) will be called magnetic flux density or  magnetic induction. The field \(vec H\) will called  magnetic intensity or magnetic field intensity

AK-47's picture 23-09-30 03:09:36 n


Node id: 5224page

Consider free fermions at temperature $T\,=\,300^o$ K. The Fermi energy is $5$ electron volt. Give a qualitative argument why the specific heat for such a system is linearly proportional to the temperature.

AK-47's picture 22-01-23 20:01:23 n

[1998TH/LNP-03]--Lecture -3 Microscopic vs macroscopic systems

Node id: 5545page
AK-47's picture 22-07-08 07:07:29 n


Node id: 5683page
AK-47's picture 22-08-14 19:08:48 n

[NOTES/EM-10006]-Maxwell's Fourth Equation, Displacement Current

Node id: 5739page

We discuss how Maxwell's addition of a displacement current in the fourth equation.


AK-47's picture 23-03-03 21:03:00 n


Node id: 5091page

The average kinetic energy of the hydrogen atoms in a certain stellar atmosphere ( assumed to be in equilibrium) is $1$ electron volt.

(a) What is the temperature in Kelvin?

(b) What is the ratio of the number of atoms in the $N=3$ state to the number in the ground state.

(c) Discuss qualitatively the ration of the number of ionized atoms to the atoms in the $N\,=\,3$ state, with out taking the density of states for the ionized atoms, i.e., taking only the Boltzmann factor. ( Taking the density of states has an interesting consequence, first pointed out by Prof. M.N.Saha . Will discuss
this in the class)

AK-47's picture 22-01-09 20:01:18 n


Node id: 5198page

The fundamental frequency of vibration of a wire of length
$L$, mass $m$, and tension $\mathcal{J}$ is given by
f_1={1\over2L} \sqrt{{\mathcal{J}L\over m}}
With what frequency of vibration with the wire of Prob. [2] vibrate
at 20$^\circ$C; $8^\circ$C? (The density of wire is $9.0\times10^3$

AK-47's picture 22-01-16 17:01:47 n


Node id: 5361page

Electrodynamics                                              Apr 19, 2019

The above image is reproduced from a book. Read Example 8.5 carefully. Answer the following questions.

  1. Do you agree that there is no flux linked with the circuit when key is open?
  2. Do you agree that there will be induced current when the circuit is closed. But the coil and the magnet remain stationary?
  3. If you disagree what is the mistake? Does the flux rule apply or not in this case?
  4. Write any other comment you may have.
AK-47's picture 22-04-04 17:04:58 n


Node id: 5426page
AK-47's picture 22-06-21 08:06:40 n

[1998TH/LNP-12]-Work in Thermodynamics

Node id: 5583page
AK-47's picture 22-07-17 11:07:46 n

[LECS/EM-03001]-Electric Potential

Node id: 5651page

The concept of electric potential for static electric field is defined as work done on a unit charge. The expression for the electric potential of a  \(q\) charge is obtained. For a system of point charges  the potential can be written down as superposition of potential due to individual charges. As an illustration we compute potential due to a dipole.

AK-47's picture 24-03-30 05:03:45 n

[NOTES/EM-07006]-Lorentz Force on a Current Distribution

Node id: 5711page

Starting from Lorentz force per unit volume on a current carrying conductor due to magnetic field is shown to be \(\vec{j}\times\vec{B}\)


AK-47's picture 24-03-05 09:03:16 n

[NOTES/QCQI-01005] Bloch Sphere

Node id: 5022page
AK-47's picture 22-04-07 13:04:01 y


Node id: 5168page

Use Maxwell's relations to find a relation between the specific heats, coefficient of thermal expansion and compressibility and show that

\[C_p= C_V+ \frac{T\alpha^2}{\kappa_T} V\]

AK-47's picture 22-01-13 18:01:38 n

[NOTES/EM-02010] Gauss Law and Use of Symmetry

Node id: 5956page

Gauss law aloe is not sufficient to determine the electric field for a given system.To determine electric field using Gauss law the symmetry of problem plays an important role by determining the direction of the electric field in given problem.

AK-47's picture 23-10-18 19:10:36 n


Node id: 5226page

Consider a particle occupying one of the three levels in a system with energies ( one level) $\epsilon_0$ and two levels $\epsilon_0\,+\,\Delta$. There are N such systems ( non-interacting) and in equilibrium at temperature $T$.

(a)Find the number $N_0$ occupying the ground state and the number $N_1$ occupying the excited states.

(b) Calculate the specific heat of the system.

AK-47's picture 22-01-23 20:01:49 n


Node id: 5399page
AK-47's picture 22-05-10 16:05:40 n

[1998TH/LNP-05] Lecture -5 Zeroth Law and Temperature

Node id: 5547page
AK-47's picture 22-07-08 07:07:13 n

[NOTES/ME-08001]-Motion in Linearly Accelerated Frames

Node id: 5685page
AK-47's picture 22-08-14 19:08:04 y