$P, Q$ and $R$ are long parallel straight wires in air,carrying currents $20 \ A, 40 \ A$ and $60 \ A$ as shown in the figure. What is the direction of the resultant force on $Q$?

In the given figure,$X$ and $Y$ are two long straight parallel conductors each carrying a current of $2\,\text{A}$. The force on each conductor is $F$ newtons. When the current in each is changed to $1\,\text{A}$ and reversed in direction,the force on each is now

$A$ straight wire of length $2 \ m$ carries a current of $10 \ A$. If this wire is placed in a uniform magnetic field of $0.15 \ T$ making an angle of $45^{\circ}$ with the magnetic field,the applied force on the wire will be

In the figure shown,a current $I_1$ is established in the long straight wire $AB$. Another wire $CD$ carrying current $I_2$ is placed in the plane of the paper. The line joining the ends of this wire is perpendicular to the wire $AB$. The force on the wire $CD$ is:

If two streams of protons move parallel to each other in the same direction,then they

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: