Cathode ray and its properties | millikan oil drop experiment

Cathode rays

Cathode rays are

Cathode rays are

Introduction to Modern Physics | Discovery of Cathode Rays | J J Thomsons | Millikan Oil Drop Experiment

Which of the following charge (s) can exist on an oil drop (in Millikan's oil drop experiment)

If g_E and g_M are the acceleration due to gravity on the surfaces of the earth and the moon respectively and if Millikan's oil drop experiment could be performed on the two surfaces, one will find the ratio electronic charge on the moon/electronic charge on the earth to be

A charges particles particle is kept in equilibrium in the electric field between the plates of millikan oil drop experiment. If the direction of the electric field between the plates is reversed, then calculate acceleration of the charged particle.