Mathematical and Physical Journal
for High Schools
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Problem P. 4670. (October 2014)

P. 4670. The diameter of a solenoid of length \(\displaystyle \ell=2\) m is \(\displaystyle D=2\) cm. The solenoid has \(\displaystyle N=2000\) turns, its axis is vertical and an upward direct current of \(\displaystyle I=10\) A flows in it. (The circuit is closed far away from the coil.) Electrons are projected towards the axis of the coil perpendicularly to it, at an initial speed of \(\displaystyle v=2.5\cdot10^6\) m/s. What is the radius of the paths of the electrons at the point which is at a distance of \(\displaystyle d=2\) cm from the turns of the coil.

(6 pont)

Deadline expired on November 10, 2014.


10 students sent a solution.
6 points:Olosz Balázs, Sal Kristóf.
5 points:Berta Dénes, Büki Máté, Orosz Bálint, Öreg Botond.
4 points:2 students.
3 points:1 student.
2 points:1 student.

Problems in Physics of KöMaL, October 2014