what is the value of charge to mass ratio of electron
Mass-to-charge ratio Some fields use the charge-to-mass ratio (Q/m) instead, which is the multiplicative inverse of the mass-to-charge ratio. The 2014 CODATA recommended value for an electron is ​e⁄me = - 7011175882002400000♠1.758820024(11)×1011 C/kg.[2]
Coulomb It is equivalent to the charge of approximately 7018624200000000000♠6.242×1018 (6995103600000000000♠1.036×10−5 mol) protons, and −1 C is equivalent to the charge of approximately 7018624200000000000♠6.242×1018 electrons.
Coulomb Since the charge of one electron is known to be about 6981160217662079999♠1.6021766208(98)×10−19 C,[7] 1 C can also be considered the charge of roughly 6.241509×10^18 electrons or +1 C the charge of that many positrons or protons, where the number is the reciprocal of 1.602177×10^−19.
Pi Ï€ is commonly defined as the ratio of a circle's circumference C to its diameter d:[9]