An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of radii $r_e,r_p$ and ${r_\alpha }$ respectively in a uniform magnetic field $B$. The relation between $r_e,r_p$ and $\;{r_\alpha }$ is
$r_e < r_p$ $=$ $\;{r_\alpha }$
$r_e < r_p$ $ <$ $\;{r_\alpha }$
$r_e < $ $\;{r_\alpha }$ $< r_p$
$r_e > r_p$ $=$ $\;{r_\alpha }$
If an electron enters a magnetic field with its velocity pointing in the same direction as the magnetic field, then
A uniform magnetic field $\vec B\,\, = \,\,{B_0}\,\hat j$ exists in a space. A particle of mass $m$ and charge $q$ is projected towards negative $x$-axis with speed $v$ from the a point $(d, 0, 0)$. The maximum value $v$ for which the particle does not hit $y-z$ plane is
A proton carrying $1\, Me V$ kinetic energy is moving in a circular path of radius $R$ in uniform magnetic field. What should be the energy of an $\alpha -$ particle to describe a circle of same radius in the same field ?........$MeV$
A charged particle projected in a limited magnetic field according to figure. The charged particle does not strike to the opposite plate provided
A car of mass $1000\,kg$ negotiates a banked curve of radius $90\,m$ on a fictionless road. If the banking angle is $45^o$, the speed of the car is ......... $ms^{-1}$