$A$ charged particle is moving in a uniform magnetic field in a circular path of radius $R$. When the energy of the particle becomes $3$ times the original, the new radius will be

In the given figure,an electron enters a magnetic field directed into the plane of the paper. It deflects in which direction?

$A$ charge of $1\,C$ is moving in a magnetic field of $0.5\,T$ with a velocity of $10\,m/s$ perpendicular to the field. The force experienced is.....$N$.

An electron,a proton,a deuteron,and an $\alpha -$ particle enter a uniform magnetic field normally with the same velocity. Which particle will have the maximum rotational frequency?

$A$ charge $+Q$ is moving upwards vertically. It enters a magnetic field directed to the north. The force on the charge will be towards

$A$ particle of mass $m$ and charge $q$,accelerated by a potential difference $V$,enters a region of a uniform transverse magnetic field $B$. If $d$ is the thickness of the region of $B$,the angle $\theta$ through which the particle deviates from the initial direction on leaving the region is given by