Notices
 

Browse & Filter

For page specific messages
For page author info
Enter a comma separated list of user names.
2644 records found.
Operations
Selected 20 rows in this page.  
Title+Summary Namesort descending Date

[NOTES/EM-02008]-Maxwell's Equations for Electrostatics-II

Node id: 5580page

The Gauss law of electrostatics follows from the Coulomb's law for a point charge and superposition principle. The Gauss law along with the Gauss divergence theorem of vector calculus imply Maxwell's first equation \[ \nabla\cdot\bar{E}=\frac{\rho}{\epsilon_0}. \] for electrostatics.

AK-47's picture 23-10-10 20:10:28 n

Quantum Field Theory --- Notes for Lectures and Problems --- [QFT-MIXED-LOT]]

Node id: 4685collection

 

AK-47's picture 22-03-01 20:03:46 n

[NOTES/EM-03007]-Work done in field of a point charge

Node id: 5644page

We discuss the path independence of the work done by static electric field. This leads to, as in mechanics, introduction of the electric potential. An expression of the electric potential is derived by an explicit computation of work done by on a unit positive charge by the electric field of a point charge \(q\). For an arbitrary distribution of charges, the electric potential is obtained by making use of the superposition principle.

AK-47's picture 24-03-30 05:03:56 n

[NOTES/QM-17007] Summary of main results on addition of angular momenta

Node id: 4820page

$\newcommand{\DD}[2][]{\frac{d^2 #1}{d^2 #2}}$ 
$\newcommand{\matrixelement}[3]{\langle#1|#2|#3\rangle}$
$\newcommand{\PP}[2][]{\frac{\partial^2 #1}{\partial #2^2}}$
$\newcommand{\dd}[2][]{\frac{d#1}{d#2}}$
$\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}}$
$\newcommand{\average}[2]{\langle#1|#2|#1\rangle}$
$\newcommand{\ket}[1]{\langle #1\rangle}$
qm-lec-17007

AK-47's picture 22-03-04 09:03:42 y

[NOTES/ME-14011]-Rotation of a Rigid Body with One Point Fixed

Node id: 5704page
AK-47's picture 22-08-17 17:08:26 y

[NOTES/EM-12003]-Fields of a Moving Point Charge

Node id: 5761page

The electromagnetic field tensor \(F_{\mu\nu}\) is a second rank Lorentz tensor. It transformation properties are used to derive the transformation properties of electric and magnetic fields under Lorentz transformations. The equation of motion of a relativistic charged particle are written down in a covariant notation.


 

AK-47's picture 23-03-03 21:03:38 n

[QUE/SM-08001] SM-PROBLEM

Node id: 5073page

For a black body of temperature \(T\), Planck's law can be used to show that the
wavelength for which the emissivity \(e(\lambda, T)\)
is maximum is given by
\[ \beta h c = 4.965 \lambda_\text{max}\]
Solar radiation has a maximum intensity near
\(\lambda = 5\times 10^{-5}\)cm. Assume
that the the sun's surface is in thermal equilibrium. Solve the above
equation numerically and determine its temperature.

AK-47's picture 22-01-13 16:01:39 n

[QUE/TH-01005] TH-PROBLEM

Node id: 5190page

A new scale is to defined in terms of ideal gas scale of
temperature. Let the difference of ice points and the steam points
be fixed at $t_s-t_i=180$ deg. If
$\displaystyle{\lim_{P_{TP}\to0}\left({P_s\over P_i}\right)}$ is
given to be 1.3661 as the best experimental value, find $t_s$ and
$t_i$ on the new scale.

AK-47's picture 22-01-14 14:01:30 n

[2008EM/HMW-03]

Node id: 5400page

IMSc-IV Physics-IV : Electricity and Magnetism Jan-Apr 2008 
Set-IV : Tutorial-III
 Electric Potential

  • Four charges $q,2q,-q,-2q$ are placed at the corners of a square of side $a$. Find the electric field at a point distance $z$ above the center of the square. \input{\QBankDir/em-que-01016}
  • The electric field due to a line segment of length $2L$, and carrying a uniform line charge $\lambda$ at a distance $d$ above the mid point is given by $$ E = \frac{1}{4\pi\epsilon_0} \, \frac{2\lambda L}{d \sqrt{d^2 +L^2}}$$ Using the above result find the electric field at a distance $z$ above the center of a square loop ( side $2L$) carrying a uniform line charge $\lambda$.
AK-47's picture 22-05-10 16:05:19 n

[1998TH/LNP-02]--Lecture -2 Mechanics vs Thermodynamics

Node id: 5544page
AK-47's picture 22-07-08 07:07:09 n

[NOTES/ME-06002a]-General Properties of Motion in One Dimension

Node id: 5676page
AK-47's picture 24-04-08 07:04:13 y

[NOTES/EM-10002]-Poynting Theorem--Examples

Node id: 5732page

By means of several examples it is shown that the energy density of electromagnetic fields equals the well known expressions of energy of solenoid and a charged capacitor. By means of example of a capacitor being charged, the presence of the displacement current leads to a consistent Ampere's law.

AK-47's picture 22-09-06 19:09:26 n

[QUE/TH-06001] TH-PROBLEM

Node id: 5160page

Two heat reservoirs, each of fixed volume $V$ are at temperatures $T_1$ and $T_2$ ( $T_1\,>\,T_2$) initially. An engine operates between the two till both of them reach the same temperature $T_3$. The specific heat $c_V$ of the reservoirs can be assumed to constant through out. The engine is back to its inital state.

  • Show that $$ T_3^2\,\geq\,T_1T_2 $$
  • Calculate the maximum work that can be extracted from the two reservoirs. ( Answer in terms of $T_1$ and $T_2$)
AK-47's picture 22-01-13 18:01:06 n

[QUE/TH-08007] TH-PROBLEM

Node id: 5218page

For a two component system with coordinates $P,V,X,Y$
($dw=-PdV+YdX$) show that the maximum workout put at constant $V$ &
$T$ is less than or equal to the decrease in free energy
($F_1-F_2$).

AK-47's picture 22-01-23 18:01:01 n

[NOTE/EM-02014] Flux of Feld of a Point Charge

Node id: 5959article
AK-47's picture 23-10-12 19:10:58 n

[2019EM/HMW-03]

Node id: 5365page

Electrodynamics                                                                     March 8, 2019                                                                                  Tutorial-III

  • The potential takes the constant value \(\phi_0\) on the closed surface \(S\) which bounds the volume \(V\). The total charge inside V is \(Q\). There is no charge anywhere else. Show that the electrostatic energy contained in the space outside of S is \(\displaystyle U_\text{E}(out)=\frac{1}{2} Q\phi_0\)
  • The line segment between \(A\) to \(B\) in the diagram below carries a uniform charge per unit length \(\lambda\). The vector \(\vec{a}\) is coincident with the segment. The vectors \(\vec{b}\) and \(\vec{c}\) point from the observation point \(\vec{r}\) to the beginning and end of \(\vec{a}\), respectively.Evaluate the integral for the potential in a coordinate-free manner by parameterizing the line source using a variable \(s\) which is zero at the point on the charged segment that is closest to \(\vec{r}\). Show thereby that \begin{eqnarray} \phi(\vec{r}) &=& \frac{\lambda}{4\pi\epsilon_0}\ln {\left|\frac{\vec{b}\cdot\vec{a}}{a} +\sqrt{\left(\frac{\vec{b}\cdot\vec{a}}{a}\right)^2 + \frac{|\vec{b}\times\vec{a}|^2}{a^2} } \right| }\nonumber\\ && -\frac{\lambda}{4\pi\epsilon_0} \ln {\left|\frac{\vec{c}\cdot\vec{a}}{a} +\sqrt{\left(\frac{\vec{c}\cdot\vec{a}}{a}\right)^2 + \frac{|\vec{b}\times\vec{a}|^2}{a^2} } \right| } \end{eqnarray}
  • Suppose the electrostatic potential of a point charge were \[V (r) =\frac{q}{4\pi\epsilon_0}\frac{1}{r^{(1+\epsilon)}}\] rather than the usual Coulomb formula.
    • Find the potential \(V(r)\) at a point at a distance \(r\) from the center of a spherical shell of radius \(R > r\) with uniform surface charge per unit area \(\sigma\). Check the Coulomb limit \(\epsilon = 0\).
    • To first order in \(\epsilon\), show that \begin{equation} \frac{V(R)-V(r)}{V(R)} =\frac{\epsilon}{2}\left[\frac{R}{r}\ln\frac{R+r}{R-r} - \ln \frac{4R^2}{R^2-r^2}\right] \end{equation}
    Since the time of Cavendish, formulas like this one have been used in experimental tests of the correctness of Coulomb’s law.
  • Find the primitive, Cartesian monopole, dipole, and quadrupole moments for each of the following charge distributions. Use the geometrical center of each as the origin.
    • Two charges \(+q\) at two diagonal corners of a square \((\pm a, \pm a, 0)\) and two minus charges \(−q\) at the two other diagonals of the square \((\pm a, \mp a, 0)\).
    • A line segment with uniform charge per unit length λ which occupies the interval \(-\ell \le z \le \ell\).` .
    • An origin-centered ring in the \(X-Y\) plane with uniform charge per unit length \(\lambda\) and radius \(R\).

 

AK-47's picture 22-04-05 16:04:07 n

[2018EM/QUIZ-02]

Node id: 5429page
AK-47's picture 22-06-21 06:06:00 n

[NOTES/EM-01006]--Hall Effect

Node id: 5510page

The Hall effect described here provided an early method to study the effect of magnetic field on a current. An expression for Hall voltage and Hall resistance is obtained in this section.

 

AK-47's picture 22-11-17 18:11:24 n

[1998TH/LNP-11]-Work in Thermodynamics

Node id: 5582page
AK-47's picture 22-07-17 11:07:24 n

Statistical Mechanics --- Notes for Lectures and Problems [SM-MIXED-LOT]

Node id: 4690collection

Statistical Mechanics

NOTES FOR LECTURES

PROBLEMS

Mixed Lot of Problems in Statistical Mechanics

 

AK-47's picture 22-01-06 21:01:50 n

Pages

 
X