An electron falling freely under the influence of gravity enters a uniform magnetic field directed towards the south. The electron is initially deflected towards:

An $\alpha$-particle travels in a circular path of radius $0.45\,m$ in a magnetic field $B = 1.2\,Wb/m^2$ with a speed of $2.6 \times 10^7\,m/s$. The period of revolution of the $\alpha$-particle is:

If a proton is projected in a direction perpendicular to a uniform magnetic field with velocity $v$ and an electron is projected along the lines of force,what will happen to the proton and electron?

$A$ proton and a deuteron with the same initial kinetic energy enter a magnetic field in a direction perpendicular to the direction of the field. The ratio of the radii of the circular trajectories described by them is

$A$ proton and an alpha particle are separately projected in a region where a uniform magnetic field exists. Their initial velocities are perpendicular to the direction of the magnetic field. If both the particles move around the magnetic field in circles of equal radii,the ratio of the momentum of the proton to the alpha particle $\left( \frac{P_p}{P_\alpha} \right)$ is

$A$ charge of $4.0 \mu C$ is moving with a velocity of $4.0 \times 10^6 \ m/s$ along the positive $y$-axis under a magnetic field $\vec{B}$ of strength $(2 \hat{k}) \ T$. The force acting on the charge is $x \hat{i} \ N$. The value of $x$ is . . . . . . .