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

$A$ wire carrying a steady current $I$ is kept in the $x$-$y$ plane along the curve $y=A \sin \left(\frac{2 \pi}{\lambda} x\right)$. $A$ magnetic field $B$ exists in the $z$-direction. The magnitude of the magnetic force on the portion of the wire between $x=0$ and $x=\lambda$ is

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.)

$A$ long straight wire carrying a current of $25 \ A$ rests on a table as shown in the figure. 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 $PQ$ rise?

The force on a current-carrying loop (radius $= R$) in a uniform magnetic field $(B)$,which is at an angle $30^{\circ}$ with the normal,will be:

$A$ conducting circular loop of radius $r$ carries a constant current $i$. It is placed in a uniform magnetic field $\overrightarrow{B}$,such that $\overrightarrow{B}$ is perpendicular to the plane of the loop. The magnetic force acting on the loop is