$A$ horizontal semi-circular wire of radius $r$ is connected to a battery through two similar springs $X$ and $Y$. The battery sends a current $I$ through the wire. $A$ uniform magnetic field $B$ is applied perpendicular to the plane of the wire,as shown in the figure. What is the force acting on each spring?

$A$ horizontal wire carries $160 \ A$ current. Below it,another wire with a linear mass density of $10 \ g \ m^{-1}$ is kept at a distance of $4 \ cm$. If the lower wire hangs in the air,what is the current in this wire when the direction of current in both wires is the same (in $A$)? $(g=10 \ m \ s^{-2} \text{ and } \mu_0=4 \pi \times 10^{-7} \ T \ m \ A^{-1})$

Two parallel conductors,each $50 \ m$ long,separated by $0.2 \ m$,experience a force of $1 \ N$. If the current in the first conductor is twice that of the second conductor,what is the current in the second conductor (in $A$)? (Given: $\mu_0 = 4 \pi \times 10^{-7} \ T \cdot m/A$)

$A$ massless square loop of wire of resistance $R$ supporting a mass $M$ hangs vertically with one of its sides in a uniform magnetic field $B$ directed outwards in the shaded region. $A$ d.c. voltage $V$ is applied to the loop. For what value of $V$ will the magnetic force exactly balance the weight of the supporting mass $M$? (side of loop $= L, g =$ acceleration due to gravity)

$A$ long wire $AB$ is placed on a table. Another wire $PQ$ of mass $1.0\, g$ and length $50\, cm$ is set to slide on two rails $PS$ and $QR$. $A$ current of $50\, A$ is passed through the wires. At what distance above $AB$ will the wire $PQ$ be in equilibrium? (in $mm$)

Three long straight wires are connected in parallel to each other across a battery of negligible internal resistance. The ratio of their resistances is $3 : 4 : 5$. What is the ratio of the distances of the middle wire from the others if the net force experienced by it is zero?