$A$ proton carrying $1\, MeV$ kinetic energy is moving in a circular path of radius $R$ in a uniform magnetic field. What should be the energy of an $\alpha$-particle to describe a circle of the same radius in the same field? ........$MeV$

$A$ 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

Two infinitely long straight wires $A$ and $B$, each carrying current $I$, are placed on the $x$ and $y$-axes, respectively. The current in wires $A$ and $B$ flows along $-\hat{i}$ and $\hat{j}$ directions, respectively. The force on a charged particle having charge $q$, moving from position $r = d(\hat{i} + \hat{j})$ with velocity $v = v\hat{i}$ is:

$A$ charged particle moves through a magnetic field perpendicular to its direction. Then

The figure shows three situations when an electron with velocity $\vec v$ travels through a uniform magnetic field $\vec B$. In each case,what is the direction of the magnetic force on the electron?

Consider the following statements regarding a charged particle in a magnetic field. Which of the statements are true?