What is the magnitude of magnetic force per unit length (in $N \;m ^{-1}$) on a wire carrying a current of $8\; A$ and making an angle of $30^o$ with the direction of a uniform magnetic field of $0.15\;T$?

Write formula for current carrying wire placed in uniform magnetic field.

The magnetic field existing in a region is given by $\overrightarrow{\mathrm{B}}=0.2(1+2 \mathrm{x}) \hat{\mathrm{k} T}$. A square loop of edge $50 \mathrm{~cm}$ carrying $0.5 \mathrm{~A}$ current is placed in $x-y$ plane with its edges parallel to the $x-y$ axes, as shown in figure. The magnitude of the net magnetic force experienced by the loop is___________. $\mathrm{mN}$.

A metallic loop is placed in a magnetic field. If a current is passed through it, then

A closed loop $PQRS$ carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments $PS, SR$ and $RQ$ are $F_1, F_2$ and $F_3$ respectively and are in the plane of the paper and along the directions shown, the force on the segment $QP$ is

A thin flexible wire of length $\mathrm{L}$ is connected to two adjacent fixed points and carries a current $\mathrm{I}$ in the clockwise direction, as shown in the figure. When the system is put in a uniform magnetic field of strength $B$ going into the plane of the paper, the wire takes the shape of a circle. The tension in the wire is