alleryThe excess pressure inside a **soap bubble** of radius $r$ and surface tension $T$ is:
A$T/r$
B$2T/r$
C$4T/r$
D$8T/r$
Answer & Solution
Correct answer: C. $4T/r$
Soap bubble has TWO air-soap interfaces (inside and outside surface of the film).
**So excess pressure doubles:** $\Delta P = 4T/r$.
(Liquid drop has one interface ⇒ $2T/r$.)
Keep practising Unit 1A: Kinematics: 1D Motion, Position & Velocity
Browse all Unit 1A: Kinematics: 1D Motion, Position & Velocity questions for AP Physics 1, or explore more Physics topics.
Related questions
The audible range of frequencies for a normal human ear is approximately:The loudness of a sound is related to its:The pitch of a sound is determined primarily by its:The maximum displacement of particles from their mean position is called the:If the frequency of a wave is f and its wavelength is λ, its speed v is given by:The time taken for one complete oscillation is the:The SI unit of frequency is the:The number of complete oscillations per second is called the: