Rank the following five capacitors in the order of the energy ...

[lak]

Rank the following five capacitors in the order of the energy they store.
   (a) a 20-F capacitor with a 4-V potential difference between its plates
   (b) a 30-F capacitor with charges of magnitude 90 C on each plate
   (c) a capacitor with charges of magnitude 80 C on its plates, differing by 2 V in potential,
   (d) a 10-F capacitor storing energy 125 J
   (e) a capacitor storing energy 250 J with a 10-V potential difference

  1.e > a > b > d > c
  2.e > d > a > b > c
  3.c > b > a > d > e
  4.b > a = c > d = e

Question 2

Can we be certain that one of the balloons in Question 2 is electrostatically charged?

[Tabitha_2016]

Answer to Question 1

1

Answer to Question 2

Yes. At least one balloon must possess a charge in order to induce a charge on the
other one, or as stated above both balloons could be charged.