Two long parallel wires are at a distance $R$ apart. They carry steady equal currents in the same directions as shown in the figure. The ratio of magnetic fields at $A, B$ and $C$ respectively, is
A$0 : 1 : 1$
B$0 : 1 : -1$
C$0 : -1 : 0$
D$1 : 0 : 0$
Medium
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B$0 : 1 : -1$
b We know, the magnetic field due to a long current carrying wire is given as
$B =\frac{\mu_0 I }{2 \pi r }$
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