GATE 2021 PI – Question 26

General Engineering · Thermal and Fluids Engineering · 1 mark · Multiple choice

Which dimensionless number is the ratio of inertial to viscous force?

Show answer and explanation

Correct answer: (D) Reynolds

Explanation

Inertial force scales as ρU²L² and viscous force as μUL. Their ratio is $\rho UL/\mu=UL/\nu$, the **Reynolds number, D**.

GATE 2021 PI Q32 – A refrigerator removes heat at 300 kJ/min to maintain its inside at 2°C. Input power is 2…
GATE 2021 PI Q33 – An ideal Otto cycle receives 800 kJ/kg during constant-volume heat addition and rejects…
GATE 2021 PI Q46 – A circular tank of diameter 4 m holds water to depth 3 m. Assuming almost steady flow and…
GATE 2021 PI Q62 – Fluid of dynamic viscosity 1 Pa·s and density 1000 kg/m³ flows at 0.2 litre/s through a 1…
GATE 2021 PI Q64 – A sphere has radius 1 m, centered at the origin, and thermal conductivity K = 50 W/(m·K).…
GATE 2026 PI Q29 – Which ONE OR MORE processes of the Carnot cycle shown are isentropic? Figure is not to…