Mechanical Engineering - MCQ Practice Questions
Core mechanical MCQs — thermodynamics, SOM, fluid mechanics for GATE & PSUs.
259 questions | 100% Free
A pump delivers 0.05 m³/s of water. If the pipe diameter is 0.1 m, the velocity of flow is:
The Darcy friction factor for fully developed laminar flow in a pipe depends on:
Water flows through a horizontal pipe with diameter 0.05 m at a velocity of 2 m/s. The volumetric flow rate is:
The Mach number is the ratio of:
For turbulent flow in pipes, the Colebrook-White equation is used to find the friction factor. Which of the following is NOT an input parameter?
A fluid element has shear stress τ = 0.5 Pa and velocity gradient du/dy = 10 s⁻¹. The dynamic viscosity of the fluid is:
The Reynolds number for flow in a circular pipe is given by Re = ρVD/μ. If the flow transitions from laminar to turbulent at Re ≈ 2300, then for a pipe with D = 0.025 m and V = 1.5 m/s (ρ = 1000 kg/m³, μ = 0.001 N·s/m²), the flow regime is:
Which of the following is a dimensionless number used in fluid mechanics that compares inertial forces to surface tension forces?
A venturi meter is used to measure fluid flow rate. The principle it operates on is:
The major loss in pipe flow (Darcy-Weisbach equation: hf = f(L/D)(V²/2g)) is primarily due to:
In a pitot tube, the stagnation pressure and static pressure are measured. The velocity at the measurement point is:
A jet of water impinges on a flat plate perpendicular to its surface. If jet velocity is 10 m/s and jet area is 0.01 m², the force on the plate is approximately:
In a U-tube manometer with mercury, if one leg shows 50 mm height difference, the pressure difference is:
For a turbulent flow in pipes, the friction factor f in the Darcy-Weisbach equation depends primarily on:
A convergent-divergent nozzle (De Laval nozzle) accelerates gas to supersonic speeds. The throat area compared to exit area is:
The Froude number characterizes the relative importance of:
A pipeline carrying oil (ν = 2 × 10⁻⁴ m²/s) has diameter 0.5 m and velocity 2 m/s. The flow regime is:
The Mach number M = 0.3 indicates:
For water flow in a pump system, cavitation occurs when:
A horizontal pipe of diameter 50 mm carries water at 2 m/s. If the pipe length is 100 m and friction factor f = 0.04, calculate the head loss using Darcy-Weisbach equation.