Home PYQs UPPSC UPPSC MCQs Prelims 2019 (GS Paper I)

Question

What happens when some charge is placed on a soap bubble ?

  1. Its radius increases
  2. Its radius decreases
  3. The bubble collapses
  4. None of the above

Answer:

Option A: Its radius increases

Detailed Solution:

The correct answer is “Its radius increases”.

When the charge is placed on the soap bubble, every part of the surface of the soap bubble has the same charge. So every part of the surface of the soap bubble will repel every other part of the surface which will increase the size (and hence radii) of the soap bubble.