The ratio of specific charge of an $\alpha $ -particle to that of a proton is
$2 : 1 $
$1 : 1$
$1 : 2$
$1 : 3$
Who produced electromagnetic waves for the first time ?
Which of the following have highest specific charge
Cathode rays are
Write dimensional formula and electron volt of electron volt.
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