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 r=8.4. The shell is charged positively, and the charge is distributed evenly such that the charge density is =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
a) E1=3.103 V/m,
b) E2=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