Solution to task 464 from Chertov´s for extramural stud

Solution to task 464 from Chertov´s for extramural stud

464. A thin copper conductor with a mass of m = 5 g is bent in the form of a square and its ends are closed. The square is placed in a uniform magnetic field (B = 0.2 T) so that its plane is perpendicular to the field lines. Determine the charge Q that will flow through the conductor if the square, pulling the opposite vertices, is pulled into a line.