3
votes
1answer
70 views

Why would a rotating charged sphere not have time varying electric field?

I have seen Gauss Law being used for a uniformly charged hollow sphere rotating with $\omega$. How is that valid to use Gauss law since it is an electrostatic law and if it is valid, why do we get a ...
2
votes
1answer
50 views

Earnshaw Theorem for ionic solids

Is a single molecule of sodium chloride (say) or a cluster of molecules of NaCl unstable, although macroscopically NaCl is in fact, stable? How can I reason this based on Earnshaw's theorem?
0
votes
1answer
56 views

phase difference between incident plane wave incident on a dipole and radiation fields from dipole

i have an incident plane wave and a dipole, consider that plane wave incident on dipole. at this moment what happen for dipole ? we know that after incident of plane wave on dipole, the radiation have ...
1
vote
1answer
453 views

Why the electric bulb turns on almost instantly when the switch is closed? [duplicate]

The electron drift speed is estimated to be very low.How could there is current almost the instant a circuit is closed?? By the discussions it is known that The information about beginning of the ...
0
votes
0answers
65 views

why boundary condition in steady electric current?

when we electric field between two conductors in certain direction the current density should pass in its direction why current density direction change at boundary although the direction of electric ...
0
votes
1answer
104 views

Fundamentals of electrostatics

Suppose I have a Gold Leaf Electroscope and the leaves are observed to diverge by a certain amount. Now if I send a beam of X-rays and allow it to fall upon the electroscope for a very short period of ...
0
votes
0answers
90 views

Curie's principle in electromagnetic field theory

I am looking for some explanation and if possible also some references about the applications of Curie's principle in electromagnetic field Theory, precisely in the computation of magnetic (resp. ...