Two particles $A$ and $B$ of masses ${m_A}$ and ${m_B}$ respectively and having the same charge are moving in a plane. A uniform magnetic field exists perpendicular to this plane. The speeds of the particles are ${v_A}$ and ${v_B}$ respectively, and the trajectories are as shown in the figure. Then

Two parallel beams of protons and electrons, carrying equal currents are fixed at a separation $d$. The protons and electrons move in opposite directions. $P$ is a point on a line joining the beams, at a distance $x$ from any one beam. The magnetic field at $P$ is $B$. If $B$ is plotted against $x$, which of the following best represents the resulting curve

A deuteron and an alpha particle having equal kinetic energy enter perpendicular into a magnetic field. Let $r_{d}$ and $r_{\alpha}$ be their respective radii of circular path. The value of $\frac{r_{d}}{r_{\alpha}}$ is equal to

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

A particle having the same charge as of electron moves in a circular path of radius $0.5
\,cm$ under the influence of a magnetic field of $0.5\,T.$ If an electric field of $100\,V/m$ makes it to move in a straight path, then the mass of the particle is (given charge of electron $= 1.6 \times 10^{-19}\, C$ )