Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main20268 April 2026Evening ShiftPhysicsMechanical Properties of FluidsActual

A spherical liquid drop of radius R acquires the terminal velocity v₁ when falls through a gas of viscosity . Now the drop is broken into 64 identical droplets and each droplet acquires terminal velocity v₂ falling through the same gas. The ratio of terminal velocities v₁/v₂ is ________.

Options

  1. A4
  2. B0.25
  3. C32
  4. D16

Correct answer

D. 16

Step-by-step solution

The terminal velocity of a spherical drop of radius r falling through a viscous medium is given by Stokes' law: v = 2 9 r^2 ( - ) g From this relation, the terminal velocity is directly proportional to the square of the radius of the drop: v r^2 When the large drop of radius R is broken into 64 identical droplets of radius r , the total volume remains conserved: 4 3 R^3 = 64 4 3 r^3 R^3 = 64 r^3 R = 4r The ratio of the terminal velocities of the original drop and the smaller droplet is: v₁ v₂ = R^2 r^2 Substituting

Practice Mechanical Properties of Fluids on Quantrex Academy →

More from Mechanical Properties of Fluids

Passage: A container of height 2 m, length 2 m and breadth 1 m is made of insulating vertical walls and two large area horizontal metal plates ( M₁ and M₂ ) which extend far beyond 2026A liquid of density 600 kg/m ^3 flowing steadily in a tube of varying cross-section. The cross-section at a point A is 1.0 cm ^2 and that at B is 20 mm ^2 . Both the points A and B 2026A cylindrical vessel of 40 cm radius is completely filled with water and its capacity is 528 dm ^3 (dm : decimeter). The vessel is placed on a solid block of exactly same height as 2026Eight mercury drops, each of radius r , coalesce to form a bigger drop. The surface energy released in this process is _______. ( S is the surface tension of mercury). 2026A water spray gun is attached to a hose of cross sectional area 30 cm ^2 . The gun comprises of 10 perforations each of cross sectional area 15 mm ^2 . If the water flows in the ho 2026The surface tension of a soap solution is 3.5 10⁻² N/m. The work required to increase the radius of a soap bubble from 1 cm to 2 cm is 10⁻⁶ J. The value of is _____. ( = 22/7 ) 2026The surface tension of a soap bubble is 0.03 N/m. The work done in increasing the diameter of bubble from 2 cm to 6 cm is 10⁻⁴ J. The value of is _______. (Take = 3.14 ) 2026If an air bubble of diameter 2 mm rises steadily through a liquid of density 2000 kg/m ^3 at a rate of 0.5 cm/s, then the coefficient of viscosity of liquid is _______ Poise. (Take 2026 Full Mechanical Properties of Fluids list All JEE Main PYQs