question_answer

Directions: 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 two straight wires AB and CD. A steady current I is flowing in the loop. Angle made by AB and CD at the origin O is \[30{}^\text{o}.\] another straight thin wire with steady current\[{{I}_{1}}\]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 2009]

A) the forces on AB and DC are zero

B) the forces on AD and BC are zero

C) 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\[\frac{{{\mu }_{0}}I{{I}_{1}}}{24ab}(b-a)\]