When cathode rays (tube voltage $~ 10 kV$) collide with the anode of high atomic weight then we get
Positive rays
$X-$rays
Gamma rays
Canal rays
In a Millikan's oil drop experiment the charge on an oil drop is calculated to be $6.35 \times {10^{ - 19}}C$. The number of excess electrons on the drop is
In a parabola spectrograph, the velocities of four positive ions $P,Q,R$ and $S$ are $v_1$, $v_2$, $v_3$ and $v_4$ respectively
An electron gun with its collector at a potential of $100\; V$ fires out electrons in a spherical bulb containing hydrogen gas at low pressure $(\sim 10^{-2} \;mm$ of $Hg$ . A magnetic field of $2.83 \times 10^{-4}\; T$ curves the path of the electrons in a circular orbit of radius $12.0 \;cm .$ (The path can be viewed because the gas tons in the path focus the beam by attracting electrons, and emitting light by electron capture; this method is known as the 'fine beam tube' method.) Determine $e / m$ from the data.
A charge of magnitude $3e$ and mass $2m$ is moving in an electric field $\overrightarrow E .$ The acceleration imparted to the charge is
An electron initially at rest, is accelerated through a potential difference of $ 200$ volt, so that it acquires a velocity $8.4 \times {10^6}m/s.$ The value of $e/m$ of electron will be