A tightly wound $100$ turns coil of radius $10 \mathrm{~cm}$ carries a current of $7 \mathrm{~A}$. The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as $4 \pi \times 10^{-7} \mathrm{SI}$ units):

Magnetic fields at two points on the axis of a circular coil at a distance of $0.05\,m$ and $0.2\,m$ from the centre are in the ratio $8 : 1$. The radius of the coil is.....$m$

Magnetic field vector component because of ...... and electric field scalar component because of ......

Two very long, straight and insulated wires are kept at $90^o$ angle from each other In $xy -$ plane as shown in the figure. These wires carry current of equal magnitude $I$, whose directions are shown in the figure. The net magnetic field at point $P$ will be

Write formula for magnetic field due to a circular current carrying loop having $\mathrm{N}$ turns and $\mathrm{R}$ radius at a point on the axis of the loop.

A current $I$ flows around a closed path in the horizontal plane of the circle as shown in the figure. The path consists of eight arcs with alternating radii $r$ and $2r$. Each segment of arc subtends equal angle at the common centre $P.$ The magnetic field produced by current path at point $P$ is