The GATE Grind

GATE 2020 ME (ME1) – Question 24

Fluid Mechanics · Dimensional analysis · 1 mark · Multiple choice

Froude number is the ratio of ______.

  1. buoyancy forces to viscous forces
  2. inertia forces to viscous forces
  3. buoyancy forces to inertia forces
  4. inertia forces to gravity forces

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (D) inertia forces to gravity forces

Explanation

Froude similarity compares inertia with gravity: $Fr=V/\sqrt{gL}$, so the force ratio is proportional to Fr². Thus the intended pair is **inertia and gravity, D**. Inertia/viscous effects correspond to Reynolds number.