Question:
A current of $2 \mathrm{~A}$ enters at the corner $\mathrm{d}$ of a square frame abcd of side $20 \mathrm{~cm}$ and leaves at the opposite corner b. A magnetic field $B=0.1 \mathrm{~T}$ exists in the space in a direction perpendicular to the plane of the frame as shown in figure. Find the magnitude and direction of the magnetic forces on the four sides of the frame.
Solution:
