Question

A soap-bubble with a radius 'r' is placed on another bubble with a radius R. Angles between the films at the points of contact will be.

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

Answer 1

The correct option is A ${120}^o$

to maintain the bubble at equilibrium, the angle between all the surfaces must be equal.

${360}^o/3={120}^o$