Question

A soap bubble with a radius 'r' is placed on another bubble with a radius R (figure) Angles between the films at the points of contact will be:

• A. ${120}^{\circ }$
• B. ${30}^{\circ }$
• C. ${45}^{\circ }$
• D. ${90}^{\circ }$

Answer 1

The correct option is A ${120}^{\circ }$

To maintain the bubble at equilibrium, the angle between all the surfaces ust be equal.

360/3=120