60 solved GATE ME questions on Fluid Mechanics, drawn from 9 exam years and grouped by year. Every question shows the official answer and a step-by-step solution.
Want to practise this topic and ask follow-up questions? Explore Success Tracker.
Revision companion
Start with Fluid Kinematics & Dynamics: continuity constrains mass transport, while Bernoulli constrains mechanical energy under additional assumptions. These original idealized-liquid exercises build selected foundations, not comprehensive coverage of viscous or compressible flow.
Our study notes and original examples support the PYQs below; they are not official exam questions or a replacement for the current syllabus.
Identify inlets, outlets, and impermeable walls of a fixed region. A is area normal to flow; v is section-average normal speed. Uniform profiles let these speeds represent streamline velocities.
Check yourself: Is there an uncounted branch, leak, or accumulation inside the region?
Steady single-inlet, single-outlet flow requires ρ₁A₁v₁ = ρ₂A₂v₂. At equal constant density, A₁v₁ = A₂v₂ = Qᵥ. A smaller area increases speed at fixed volume flow, not mass flow.
Check yourself: Did you justify canceling density before equating volume flow rates?
For steady incompressible inviscid flow along one streamline, with gravity and no machinery energy exchange, p + ρv²/2 + ρgz is constant. Using section averages without a kinetic-energy correction additionally assumes uniform velocity profiles at those sections.
Check yourself: Can friction, a pump, or different streamlines invalidate your comparison?
Use a common pressure datum and elevation origin. Gauge pressures can share the same atmospheric reference because only their difference enters. Cancel elevation terms only for equal elevations.
Check yourself: Does a pressure decrease supply increased kinetic energy, elevation, or both?
Neglecting viscosity removes wall friction and dissipation, but not every liquid flow is lossless. Nonuniform profiles and losses require a fuller energy balance. Constant temperature keeps the liquid-property model fixed here.
Check yourself: Which missing physical effect would require an additional term?
Original teaching example · not a PYQ
Original example: steady, isothermal liquid flow has constant density 1000 kg/m³ in a rigid horizontal contraction with impermeable walls. Sections on the same streamline have uniform profiles, A₁ = 0.02 m², A₂ = 0.01 m², v₁ = 2 m/s, and p₁ = 150 kPa gauge. Assume inviscid slip walls, no friction or minor losses, and no pumps or turbines. Find Qᵥ, v₂, and p₂.
Qᵥ = 0.04 m³/s; v₂ = 4 m/s; p₂ = 144 kPa gauge.
Separate original check: use the same steady, isothermal, incompressible, inviscid model with rigid impermeable slip walls, no losses, and no machinery. Both sections on one streamline have uniform profiles and area 0.01 m². For Qᵥ = 0.02 m³/s, ρ = 1000 kg/m³, g = 10 m/s², and an outlet 3 m higher, find p₂ when p₁ = 160 kPa gauge.
p₂ = 130 kPa gauge, referenced to the same atmosphere.
Both speeds equal 2 m/s, so kinetic terms cancel. Elevation increases pressure-equivalent potential energy by ρgΔz = 30000 Pa = 30 kPa. Thus p₂ = 160 − 30 = 130 kPa.
Supplemental reading, not an official GATE reading list or an endorsement of these notes.
Free supplemental notes deriving conservation of mass for a fluid element; connect the local equation to the section balance.
Free supplemental class-note PDFs on streamline motion and Bernoulli. Use the Class Notes links; the listed commercial textbooks are not required.
This page shows 60 recent questions from the released archive, newest first. For older questions and complete papers, browse all GATE ME papers. Questions can carry more than one subject tag; counts are not marks weightage.
Continue learning with Success Tracker
Reading a solution is a useful start. In Success Tracker, you can attempt questions yourself, review mistakes and return to the topics that need another pass.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
