An electron is moving along $+x$ direction with a velocity of $6 \times 10^{6}\, ms ^{-1}$. It enters a region of uniform electric field of $300 \,V / cm$ pointing along $+ y$ direction. The magnitude and direction of the magnetic field set up in this region such that the electron keeps moving along the $x$ direction will be
$5 \times 10^{-3} T ,$ along $+ z$ direction
$3 \times 10^{-4} T ,$ along $- z$ direction
$3 \times 10^{-4} T ,$ along $+ z$ direction
$5 \times 10^{-3} T ,$ along $- z$ direction
A proton and an alpha particle are separately projected in a region where a uniform magnetic field exists. Their initial velocities are perpendicular to direction of magnetic field. If both the particles move around magnetic field in circles of equal radii, the ratio of momentum of proton to alpha particle $\left( {\frac{{{P_p}}}{{{P_\alpha }}}} \right)$ is
A proton moving with a constant velocity, passes through a region of space without change in its velocity. If $E$ $\& B$ represent the electric and magnetic fields respectively, this region may have
An electron is moving along $+x$ direction. To get it moving along an anticlockwise circular path in $x-y$ plane, magnetic field applied along
Mixed $H{e^ + }$ and ${O^{2 + }}$ ions (mass of $H{e^ + } = 4\,\,amu$ and that of ${O^{2 + }} = 16\,\,amu)$ beam passes a region of constant perpendicular magnetic field. If kinetic energy of all the ions is same then
Two charged particles traverse identical helical paths in a completely opposite sense in a uniform magnetic field $B = B_0 \hat k$ .