Question

Check that the ratio ke²/G m_em_p is dimensionless. Look up a Table of Physical
Constants and determine the value of this ratio. What does the ratio signify?

Answer 1

The given ratio is ke²/Gm_em_p . Where,
G = Gravitational constant. Its unit is N m² kg⁻²

m_e and m_p = Masses of electron and proton and their unit is kg. 

e = Electric charge. Its unit is C.

This is the ratio of electric force to the gravitational force between a proton and an electron, keeping distance between them constant.