Millikan droplet

Question

Millikan determined the charge on the electron by studying the static charges on oil drops falling in an electric field. A student carried out this experiment using several oil drops for her measurements and calculated the charges on the drops. She obtained the following data:
Droplet
Calculated Charge (C)
A
1.60×10 ^{− 19}
B
3.15×10⁻¹⁹
C
4.81×10⁻¹⁹
D
6.31×10⁻¹⁹

 

-What is the significance of the fact that the droplets carried different charges?

-What value should she report for the electronic charge? Express your answer using three significant figures.

Answer 1

1.587x10^-19. Just by looking at the 4 values, you can tell they are approximate multiples of 1.6x10^-19 and this being the smallest of the 4 values, it is most likely the charge of one electron. The sum of all the charges is 15.87x10^-19. hence the first value is for one electron, the second for 2, the third for 3 and the for 4 all adding up to 10 electrons. to get the average charge, simp[ly divide 1.587x10^-19 by 10.