The magnetic field at the centre of a circular coil of radius $r$ carrying current $I$ is ${B_1}$. The field at the centre of another coil of radius $2 r$ carrying same current $I$ is ${B_2}$. The ratio $\frac{{{B_1}}}{{{B_2}}}$ is
$0.5$
$1$
$2$
$4$
A current $I$ flowing through the loop as shown in the adjoining figure. The magnetic field at centre $O$ is
A current of $i$ ampere is flowing through each of the bent wires as shown the magnitude and direction of magnetic field at $O$ is
Two circular loops having same radius $[ R =10\, cm ]$ and same current $\frac{7}{2} A$ are placed along same axis as shown. If distance between their centre is $10\, cm$, find net magnetic field at of point $P.$
For the magnetic field to be maximum due to a small element of current carrying conductor at a point, the angle between the element and the line joining the element to the given point must be.......$^o$
Magnetic field at the centre $O$ due to the given structure is