Two wires A & B are carrying currents I1 and I2 as shown in the figure. The separation between them is d. A third wire C carrying a current I is to be kept parallel to them at a distance x from A such that the net force acting on it is zero. The possible values of x are:

• A. \({\rm{x}} = \left( {\frac{{{{\rm{I}}_1}}}{{{{\rm{I}}_1} - {{\rm{I}}_2}}}} \right){\rm{d\;and\;x}} = \left( {\frac{{{{\rm{I}}_2}}}{{{{\rm{I}}_1} + {{\rm{I}}_2}}}} \right){\rm{d}}\)
• B. \({\rm{x}} = \left( {\frac{{{{\rm{I}}_2}}}{{{{\rm{I}}_1} + {{\rm{I}}_2}}}} \right){\rm{d\;and\;x}} = \left( {\frac{{{{\rm{I}}_2}}}{{{{\rm{I}}_1} - {{\rm{I}}_2}}}} \right){\rm{d}}\)
• C. \({\rm{x}} = \left( {\frac{{{{\rm{I}}_1}}}{{{{\rm{I}}_1} + {{\rm{I}}_2}}}} \right){\rm{d\;and\;x}} = \left( {\frac{{{{\rm{I}}_2}}}{{{{\rm{I}}_1} - {{\rm{I}}_2}}}} \right){\rm{d}}\)
• D. \({\rm{x}} = \pm \left( {\frac{{{{\rm{I}}_1}}}{{{{\rm{I}}_1} - {{\rm{I}}_2}}}} \right){\rm{d}}\)