In the given figure,what is the ratio of the magnetic force on wire $ab$ to that on wire $bc$? (Given $ab = l$ and $\angle abc = 45^o$)

$A$ straight horizontal conducting rod of length $L$ and mass $M$ is suspended by two vertical wires at its ends. If $I$ is the current passing through the rod,then in order that the tension in the wires is zero,the magnetic field set up normal to the conductor is (Neglect the mass of the wire,$g$ = acceleration due to gravity).

$A$ current $i = 2 \, A$ flows through a wire frame as shown in the figure. The frame is a combination of two equilateral triangles $ACD$ and $CDE$ with side length $1 \, m$. It is placed in a uniform magnetic field $B = 4 \, T$ acting perpendicular to the plane of the frame. The magnitude of the net magnetic force acting on the frame is.......$N$.

Assertion $(A):$ $A$ wire is bent into an irregular shape with the points $P$ and $Q$ fixed. If a current $I$ is passed through the wire,then the area enclosed by the irregular portion of the wire increases.
Reason $(R):$ Wires carrying currents in opposite directions repel each other.

Two parallel conductors $A$ and $B$ of equal lengths carry currents $I$ and $10\, I$,respectively,in the same direction. Then

Two long parallel conductors,separated by a distance $d$,carry currents $I_1$ and $I_2$ in the same direction. They exert a force $F$ on each other. Now,the current in one of them is increased to $2I$ and its direction is reversed. The distance between them is also increased to $3d$. The new value of the force between them is: