As shown in the figure, a wire is bent to form a $D$-shaped loop carrying current $I$, where the curved part is a semi-circle of radius $R$. The loop is placed in a uniform magnetic field $\overrightarrow{B}$, which is directed into the plane of the paper. The net magnetic force on the closed loop is:

$A$ straight wire carrying a current $i_1 \, A$ runs along the axis of a circular loop carrying a current $i_2 \, A$. The force of interaction between the two current-carrying conductors is

The horizontal component of the Earth's magnetic field at a certain place is $3 \times 10^{-5} \, T$ and the direction of the field is from geographic south to geographic north. $A$ very long straight conductor is carrying a steady current of $1 \, A$. Calculate the force per unit length on it if the direction of the current is from east to west (in $N/m$).

$A$ wire carrying current $I$ is tied between points $P$ and $Q$ and is in the shape of a circular arc of radius $R$ due to a uniform magnetic field $B$ (perpendicular to the plane of the paper,shown by $\times \times \times $) in the vicinity of the wire. If the wire subtends an angle $2\theta_0$ at the centre of the circle (of which it forms an arc),then the tension in the wire is:

Three parallel wires $a$, $b$, and $c$ carrying currents $i_a$, $i_b$, and $i_c$ as shown in the figure are placed next to each other. The magnitude of the force on a length $l$ of the wire $a$, if $d_2 = 2 d_1$, $i_b = i_a$, and $i_c = 4 i_a$ is:

The force acting per unit length on a very long straight conductor carrying a steady current of $1 \,A$ flowing from south to north is: (The horizontal component of the earth's magnetic field at the place is $3 \times 10^{-5} \,T$ and its direction is from geographical south to geographical north.)