Concepts Of Physics MCQ Edition [Volume 1]PhysicsSome Mechanical Properties of Matter
Determine the excess pressure inside a soap bubble having a radius of 4 mm . The surface tension of the soap solution is given as 0.03 N/m .
Options
- A7.5 N/m ^2
- B30 N/m ^2
- C15 N/m ^2
- D60 N/m ^2
Correct answer
B. 30 N/m ^2
Step-by-step solution
The excess pressure inside a soap bubble is given by the formula: P = 4T R where T is the surface tension and R is the radius of the bubble. Given T = 0.03 N/m and R = 4 mm = 4 10⁻³ m . Substituting the values: P = 4 0.03 4 10⁻³ P = 0.03 10⁻³ = 30 N/m ^2