Three long straight wires are carrying current as shown in the diagram. The magnetic force per unit length on wire $Q$ is $..... \times 10^{-7} \ N/m$.

$A$ large current-carrying plate is kept along the $y-z$ plane with $k \text{ A/m}$ current per unit length in the $+y$ direction. Find the net force on the semicircular current-carrying loop lying in the $x-y$ plane. The radius of the loop is $R$,the current is $i$,and the center is at $(d, 0, 0)$ where $d > R$.

$AB$ and $CD$ are smooth parallel rails,separated by a distance $l$,and inclined to the horizontal at an angle $\theta$. $A$ uniform magnetic field of magnitude $B$,directed vertically upwards,exists in the region. $EF$ is a conductor of mass $m$,carrying a current $i$. If the conductor is in equilibrium,find the relation between the given parameters.

$A$ long straight wire carrying a current of $25 \,A$ rests on a table. Another wire $PQ$ of length $1 \,m$ and mass $2.5 \,g$ carries the same current but in the opposite direction. The wire $PQ$ is free to slide up and down. To what height $h$ will wire $PQ$ rise (in $\,mm$)? (Take $g = 9.8 \,m/s^2$ and $\mu_0 = 4 \pi \times 10^{-7} \,T \cdot m/A$)

$A$ rectangular loop of sides $25 \text{ cm}$ and $10 \text{ cm}$ carrying a current of $10 \text{ A}$ is placed with its longer side parallel to a long straight conductor $10 \text{ cm}$ apart carrying a current of $25 \text{ A}$. The net force on the loop is

$A$ rod of mass $M$ and length $l$ is suspended by two wires $P$ and $Q$. $A$ uniform magnetic field $B$ is directed into the page. When current $I$ flows through the rod,the tension in each supporting wire is: