A particle with charge to mass ratio, $\frac{q}{m} = \alpha $ is shot with a speed $v$ towards a wall at a distance $d$ perpendicular to the wall. The minimum value of $\vec B$ that exist in this region perpendicular to the projection of velocity for the particle not to hit the wall is
$\frac{v}{{\alpha d}}$
$\frac{2v}{{\alpha d}}$
$\frac{v}{{2\alpha d}}$
$\frac{v}{{4\alpha d}}$
An electron moving with a uniform velocity along the positive $x$-direction enters a magnetic field directed along the positive $y$-direction. The force on the electron is directed along
A particle of mass $0.6\, g$ and having charge of $25\, nC$ is moving horizontally with a uniform velocity ${\rm{1}}{\rm{.2}} \times {\rm{1}}{{\rm{0}}^{\rm{4}}}\,m{s^{ - 1}}$ in a uniform magnetic field, then the value of the magnetic induction is $(g = 10\,m{s^{ - 2}})$
Two charged particles traverse identical helical paths in a completely opposite sense in a uniform magnetic field $B = B_0 \hat k$ .
A particle with charge $-Q$ and mass m enters a magnetic field of magnitude $B,$ existing only to the right of the boundary $YZ$. The direction of the motion of the $m$ particle is perpendicular to the direction of $B.$ Let $T = 2\pi\frac{m}{{QB}}$ . The time spent by the particle in the field will be
$1$ $\mathrm{T}$ $=$ ...... Guass.