• # question_answer Directions Q. Nos. 13 are based on the following paragraph. A current loop ABCD is held fixed on the plane of the paper as shown in the figure. The arcs BC (radius =b) and DA (radius = a) of the loop are joined by the straight wires AB and CD. A steady current $I$ is flowing in the loop. Angle made by A B and CD at the origin O is 30°. Another straight thin wire with steady current ${{I}_{2}}$ flowing out of the plane of the paper is kept at the origin. Due to the presence of the current ${{I}_{1}}$ at the origin:     AIEEE  Solved  Paper-2009 A) the forces on AB and DC are zeroB) the forces on AD and BC are zeroC) the magnitude of the net force on the loop is given by$\frac{{{I}_{1}}I}{4\pi }{{\mu }_{0}}\left[ 2(b-a)+\frac{\pi }{3}(a+b) \right]$D) the magnitude of the net force on the loop is given by$\frac{{{\mu }_{0}}I{{I}_{1}}}{24ab}(b-a)$

$\overrightarrow{F}=I(\overrightarrow{\ell }\times \overrightarrow{B})=0$