Mathematical and Physical Journal
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Problem P. 4420. (February 2012)

P. 4420. The root-mean-square (r.m.s.) value of the voltage of the 50 Hz mains is 230 V. The r.m.s. value of the voltage across a condenser of a series RLC circuit is 100 V, and that of across the ohmic resistor is 200 V. The r.m.s. value of the current in the circuit is 200 mA. What is the relative permeability constant of the iron core of the coil, if the length of the coil is 8 cm, its cross section is 4 cm2 and its number of turns is 300?

(5 pont)

Deadline expired on March 12, 2012.


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

Megoldás. \(\displaystyle \mu_{\rm rel}\approx 6000.\)


Statistics:

66 students sent a solution.
5 points:Antalicz Balázs, Barta Szilveszter Marcell, Bingler Arnold, Bojtár Orsika, Bolgár Dániel, Csáky Pál, Csathó Botond, Csóka József, Czigány Máté Gábor, Dávid Bence, Dinev Georgi, Dolecsek 888 Gellért, Filep Gábor, Fonyó Viktória, Garami Anna, Gujás István, Herczeg Ferenc, Horicsányi Attila, Horváth Dániel, Juhász Péter, Kollarics Sándor, Koncz Gabriella, Kozák Ádám András, Laczkó Zoltán Balázs, Mázik László, Nagy Lajos, Nagy Zsuzsika, Olosz Balázs, Papp Roland, Park Choong Eun, Pataki Bálint Ármin, Péterffy Gábor, Pölöskei Péter Zsolt, Sárvári Péter, Seress Dániel, Sisák Mária Anna, Szabó 928 Attila, Székely Eszter, Szélig Áron, Szigeti Bertalan György, Szilágyi 585 Dezső, Táczi István, Takács 737 Gábor, Tilk Bence, Tuza Réka, Ürge László, Vajda Balázs, Varga 555 Dávid.
4 points:10 students.
3 points:2 students.
2 points:2 students.
1 point:1 student.
0 point:1 student.
Unfair, not evaluated:2 solutions.

Problems in Physics of KöMaL, February 2012