Question

In the figure shown a semicircular wire loop is placed in uniform magnetic field B = 1.0 T.The plane of the loop is perpendicular to the magnetic field. Current i= 2A flows in the loop in the direction shown. Find the magnitude of the magnetic force in both the cases(a) and (b). The radius of the loop is 1.0 m

Answer 1

Refer figure (a) : It forms a closed loop and the current completes the loop. Therefore, net force on the loop in uniform field should be zero.

Refer figure (b) : In this case although it forms a closed loop, but current does not complete the loop. Hence, net force is not zero.