A metal plate gets heated, when cathode rays strike against, it due to
Kinetic energy of cathode rays
Potential energy of cathode rays
Linear velocity of cathode rays
Angular velocity of cathode rays
The colour of the positive column in a gas discharge tube depends on
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
The charge on electron was discovered by
In Bainbridge mass spectrograph a potential difference of $1000 V$ is applied between two plates distant $1$ cm apart and magnetic field in $B = 1T$. The velocity of undeflected positive ions in m/s from the velocity selector is
From the following, what charges can be present on oil drops in Millikan's experiment
(Here e is the electronic charge)