Mathematical and Physical Journal
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Problem P. 4576. (November 2013)

P. 4576. The outer radius of a spherical shell, made of insulating material, is r2=0.2 m, and its inner radius is r1=0.15 m. The relative dielectric constant of its material is \varepsilonr=8.4. The shell is charged positively, and the charge is distributed evenly such that the charge density is \varrho=10-5 C/m3. Measured from the centre of the spherical shell where are those points at which the magnitude of the electric field strength is

aE1=3.103 V/m,

bE2=3.104 V/m?

(5 pont)

Deadline expired on December 10, 2013.


Sorry, the solution is available only in Hungarian. Google translation

Megoldásvázlat. \(\displaystyle a)\) A gömb középpontjától 0,17 m és 0,76 m távol;

\(\displaystyle b)\) 0,24 m távolságban.

(A változó dielektromos állandó miatt a gömbhéj külső felületénél az elektromos térerősségnek ,,ugrása'' van; a felületen ,,polarizációs töltéssűrűség'' alakul ki.)


Statistics:

35 students sent a solution.
5 points:Balogh Menyhért, Berta Dénes, Büki Máté, Csibi Levente, Di Giovanni Márk, Dinev Georgi, Fehér Zsombor, Forrai Botond, Janzer Barnabás, Kaposvári Péter, Olosz Balázs, Trócsányi Péter, Virágh Anna.
4 points:Blum Balázs.
3 points:14 students.
2 points:6 students.
0 point:1 student.

Problems in Physics of KöMaL, November 2013