the magnetic induction at $O$ due to the whole length of the conductor is

The magnetic induction at the centre $O$ of the current carrying bent wire shown in the adjoining figure is

A length $L$ of wire carries a steady current $I$. It is bent first to form a circular plane coil of one turn. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre caused by the same current is

The current of $1\,A$ is passed through a hexagonal conducting wire of side $1\,m$ . The magnetic induction at its centre $O$ in $Wb/m^2$ will be

A long, straight wire is turned into a loop of radius $10\,cm$ (see figure). If a current of $8\, A$ is passed through the loop, then the value of the magnetic field and its direction at the centre $C$ of the loop shall be close to

Charge $q$ is uniformly spread on a thin ring of radius $R.$ The ring rotates about its axis with a uniform frequency $f\, Hz.$ The magnitude of magnetic induction at the center of the ring is