Who discovered the ratio of charge to mass of electon and how ? Expalin with diagram

Explanation

Value of `e//m_(c ) : ` in 1897 J.J. Thomson measured the ratio of electrical charge (e ) to the mass of electron `e//m_(c ) = 1.758820 xx 10^(11) C kg^(-1) (equ 2.1)`
Where `m_(e ) = ` mass of the electron in kg
the electron in coloumb

Expeiment - Dtermination method of `e//m_(e ) :` thomson used cathode ray tube to get the value of `e//m_(s )` Thomson applied electrical and magnetic field perpendicular to each other on the path electron
Observation :
When only electric field applied the electrons the deviate from their path and and hit the cathode ray at point A .Simillary when only magnetic field is applied electron sirlkes the cathode ray point C. by carefully balancing the electrical adn magnetic field strength it is possible to bring screen at point B
By crrying accurate measurements thomson was able th determine the value of `e//m_(e )`