Question

Column II gives four situations in which three or four semi-finite current carrying wires are placed in x-y plane. The magnitude of the direction of current is shown in each figure. Column I gives statements regrading the x- and y- components of magnetic field at point $P$ whose coordinates are $(0,0,d)$. Match the statements in Column I with the corresponding figures in Column II.

Answer 1

The magnetic field is along negative y-direction in cases (1), (2) and (3).
In case(4), there is a component of magnetic field along -ve x-axis.
Hence, A $\to$ 1, 2, 3

Z-component of magnetic field is zero in all cases.
Hence, B $\to$ 1, 2, 3, 4

The magnitude of the magnetic field in case(3) is $\frac{{\mu }_{0}i}{4\pi d}$.

The magnetic field at P is less than $\frac{{\mu }_{0}i}{2\pi d}$ in all cases.

Hence, C $\to$ 3
Hence, D $\to$ 1, 2, 3, 4