Problem 3.300

A square wire frame with side $a$ and a straight conductor carrying a constant current $I$ are located in the same plane (Fig. 3.86).

The inductance and the resistance of the frame are equal to $L$ and $R$ respectively. The frame was turned through $180^{\circ}$ about the axis $00^{\prime}$ separated from the current-carrying conductor by a distance $b$. Find the electric charge having flown through the frame.