Q66
General SciencePhysics
A soap bubble is given a negative charge, then its radius
- a.decreases
- b.increases
- c.remains unchanged
- d.nothing can be predicted as information is insufficient
Answer: (B) increases
Charge of either sign spreads over the bubble's surface, and the like charges repel each other, producing an outward electrostatic pressure. This adds to the gas pressure inside, so the bubble expands and its radius increases; the sign of the charge does not matter.