The mass of a particle is $400$ times than that of an electron and the charge is double. The particle is accelerated by $5 V$. Initially the particle remained in rest, then its final kinetic energy will be ........... $eV$
$5$
$10$
$100$
$2000$
In the Millikan's experiment, the distance between two horizontal plates is $2.5 \,\,cm$ and the potential difference applied is $250\,\, V$ . The electric field between the plates will be ....... $V/m$
Three particles having their charges in the ratio of $1 : 3 : 5$ produce the same spot on the screen in Thomson’s experiment. Their masses are in the ratio of
In Thomson spectrograph experiment, four positive ions $P,Q,R$ and $S$ are situated on $Y-X$ curve a shown in the figure
Cathode rays enter into a uniform magnetic field perpendicular to the direction of the field. In the magnetic field their path will be
Who produced electromagnetic waves for the first time ?