Question

A soap bubble is given a negative charge, then its radius

Answer 1

Explanation,

1. The charge is distributed uniformly all over the surface of the bubble at the symmetry of the soap bubble.
2. In such a phenomenon, they will tend to move even further apart as like charges repel. This can occur only in a way that is outward.
3. This will take the soap surface with them and increases the restoring force of the soap film.
4. This surface tension will be equal to and the opposite of the electric force acting.
5. As a result of this, the equilibrium radius will be a new increased radius.
6. This can occur in both positive and negatively charged bubbles due to their ionic similarity.
7. Therefore we can conclude that when the soap bubble is given a positive charge or negative charge, then the radius of the soap bubble will increase.

Hence, when a soap bubble is given a negative charge, then the radius of the soap bubble will increase.