The motion of a charged particle can be used to distinguish between a magnetic field and an electric field in a certain region by firing the charge:

$A$ particle of mass $0.6 \,g$ and having charge of $25 \,nC$ is moving horizontally with a uniform velocity $1.2 \times 10^4 \,ms^{-1}$ in a uniform magnetic field. The value of the magnetic induction is $\left(g=10 \,ms^{-2}\right)$.

An $\alpha$-particle and a proton travel with the same velocity in a magnetic field perpendicular to the direction of their velocities. Find the ratio of the radii of their circular paths.

$A$ proton is moving along the $Z$-axis in a magnetic field. The magnetic field is along the $X$-axis. The proton will experience a force along

$A$ charged particle enters a uniform magnetic field perpendicular to its velocity. The magnetic field:

An electron is moving along the positive $X$-axis. You want to apply a magnetic field for a short time so that the electron may reverse its direction and move parallel to the negative $X$-axis. This can be done by applying the magnetic field along