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.)

Three long straight wires $A$,$B$,and $C$ are carrying currents as shown in the figure. Then the resultant force on $B$ is directed .....

$A$ wire carrying current $I$ along the $x$-axis has length $\ell$ and is kept in a magnetic field $\vec{B} = (\hat{i} + 2\hat{j} - 3\hat{k}) B \text{ Wb/m}^2$. The magnitude of the magnetic force acting on the wire is:

In the given diagram, the loop tends to:

Heart-lung machines and artificial kidney machines employ blood pumps. $A$ mechanical pump can mangle blood cells. The figure represents an electromagnetic pump. The blood is confined to an electrically insulating tube, represented as a rectangle of width $\omega$ and height $h$. Two electrodes fit into the top and the bottom of the tube. The potential difference between them establishes an electric current through the blood, with current density $J$ over a section of length $L$. $A$ perpendicular magnetic field $B$ exists in the same region. The section of liquid in the magnetic field experiences a pressure increase given by:

Three straight parallel current-carrying conductors are shown in the figure. The force experienced by the middle conductor of length $25\, cm$ is