Equal currents are passing through two very long and straight parallel wires in the same direction. They will . . . . . . .

Two long straight wires $P$ and $Q$ carrying equal current $10\,A$ each were kept parallel to each other at $5\,cm$ distance. Magnitude of magnetic force experienced by $10\,cm$ length of wire $P$ is $F_1$. If distance between wires is halved and currents on them are doubled,force $F_2$ on $10\,cm$ length of wire $P$ will be :

Two thin long parallel wires,separated by a distance $d$,carry a current of $I$ $A$ in the same direction. They will:

$A$ uniform magnetic field of $1.5\; T$ exists in a cylindrical region of radius $10.0\; cm$,its direction parallel to the axis along east to west. $A$ wire carrying current of $7.0\; A$ in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if,
$(a)$ the wire intersects the axis,
$(b)$ the wire is turned from $N-S$ to northeast-northwest direction,
$(c)$ the wire in the $N-S$ direction is lowered from the axis by a distance of $6.0 \;cm?$

As shown in the figure, a metallic rod of linear density $0.45\,kg\,m^{-1}$ is lying horizontally on a smooth inclined plane which makes an angle of $45^{\circ}$ with the horizontal. The minimum current flowing in the rod required to keep it stationary, when a $0.15\,T$ magnetic field is acting on it in the vertical upward direction, will be $....A$ $\{$Use $g=10\,m/s^2\}$

Three long current-carrying wires $P, Q,$ and $R$ are placed perpendicular to the plane of the paper as shown. The magnetic force per unit length on wire $R$ is: