Two very thin metallic wires placed along X- and Y-axes carry equal currents as shown in Fig. AB and CD are lines at `45^@` with the axes. The magnetic field will be zero on the line

Options

A. AB
B. CD
C. segment OB only of line AB
D. segment OC only of line CD.

Answer

A

Explanation

(a) All points on AB are equidistant from the two wires. So,
magnetic field are equal and opposite. Thus, they cancel out.