Two very thin metallic wires placed along `X` and `Y` axes carry equal currents as shown `AB` and `CD` are lines at `45^(@)` with the axes having origin at `O` 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

For AB-
Applying right hand thumb rule, the direction of B due to one current is upward and that due to other is downward. Both cancel out each other and `B_("net") =0`
For CD -
The direction of B is in the same direction in both case giving non zero resultant.