Question

Two long straight wires are placed along $x$-axis and $y$-axis. They carry current $I_1$ and $I_2$ respectively. The equation of locus of zero magnetic induction in the magnetic field produced by them is

• A. $y=x$
• B. $y=\left(\frac{I_2}{I_1}\right)x$
• C. $y=\left(\frac{I_1}{I_2}\right)x$
• D. $y=\left(I_1{I}_2\right)x$

Answer 1

Answer: (C)

On a general point $A$ magnetic field will be zero when $\frac{{\mu }_0{I}_2}{2\pi x}=\frac{{\mu }_0{I}_1}{2\pi y}$
$y=\frac{I_1}{I_2}x$