Question

Electric flux coming out of a single Na^+ ion is _________ Nm^2C^-1

(a) 1.8*10^-8

(b) 1.8*10^-10

(c) 5.4*10^-8

(d) 3.6*10^-8

I had been asked this question in final exam.

Asked question is from Application of Gauss’s Law in chapter Charges and Fields of Physics – Class 12

Answer 1

Right answer is (a) 1.8*10^-8

For explanation I would say: A single Na^+ ion means a single sodium atom without an electron. The charge of the ion is the same as the charge of an electron but positive i.e. +1.602*10^-19C. Therefore, applying Gauss’s Law, electric flux coming out of the ion = \(\frac {charge \, of \, the \, ion}{\varepsilon}\). Substituting the values, we get flux = 1.8*10^-8 Nm^2C^-1.