Question

How many electrons move past a fixed reference point every t = 1.15 ps if the current is i = -2.7 μa ?

Answer 1

As per the question,the current amplitude is given as i= -2.7 micro ampere

                                                                                      i.e -2.7 ×$10^{-6}$

as per the question the time is given as t=1.15s

we know that $i=\frac{q}{t}$

                         hence q=i×t

hence the total charge passing through this point is given as

                         q= -2.7×$10^{-6}$× 1.15

                             = -3.105×$10^{-6}$

we know that q=ne where n is the number of electrons and e is the charge of electron

we have e= -1.602×$10^{-19}$ coulomb

hence number of electrons n=$\frac{q}{e}$

                         = 3.105×$10^{-6}$×$\frac{1}{1.602*10^{-19} }$

                         =1.93820×$10^{13}$