Question

Which is true about an electron-
(a). rest mass of electron is `9.1xx10^(-28)g`
(b). mass of electron increases with the increase in velocity
(c). molar mass of electron is `5.48xx10^(-4)g//"mole"`
(d). `e//m` of electron is `1.7xx10^(8) "coulomb"//g`
A. Rest mass of electron is `9.1 xx10^(-28)`g
B. Mass of electron increases with the increase in velocity
C. Molar mass of electron is `5.48xx10^(-4)` g/mole
D. e/m of electron is `1.7xx10^(8)` coulomb/g

Answer 1

Correct Answer - a,b,c
(b) As energy also has mass ,so K.E of `e^(-) uarr ,"mass" uarr `
(c ) molar mass `=6.023 xx10^(23)xx9.1xx10^(-28)` g / mole
(d) `e//m =(1.6xx10^(-19))/(9.1xx10^(-28)) c//g`