Mechanical Engineering - MCQ Practice Questions

A fluid with dynamic viscosity μ = 0.8 Pa·s and density ρ = 800 kg/m³ flows through a pipe. What is the kinematic viscosity?

For laminar flow in a circular pipe, the Hagen-Poiseuille equation gives volumetric flow rate as Q = πΔPd⁴/(128μL). This assumes:

Which of the following statements about boundary layers is correct?

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:

For flow through an orifice, the discharge coefficient Cd is always:

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:

In open channel flow, the critical depth occurs when:

A pipeline carrying oil (ν = 2 × 10⁻⁴ m²/s) has diameter 0.5 m and velocity 2 m/s. The flow regime is:

For a submerged curved vane deflecting a jet, the component of force in the direction of jet is:

The Mach number M = 0.3 indicates:

For water flow in a pump system, cavitation occurs when:

The equivalent length method for minor losses in pipes replaces a fitting with an equivalent length of pipe. For a 90° elbow with diameter 50 mm, typical equivalent length is:

In a centrifugal pump, the impeller diameter is doubled while keeping speed constant. The head capacity changes by factor of:

For steady flow of an incompressible fluid through a variable area duct, which equation relates velocities at different sections?

A fluid undergoes viscous deformation with velocity gradient du/dy = 50 s⁻¹. For Newtonian fluid with μ = 0.1 Pa·s, the shear stress is:

A fluid with dynamic viscosity μ = 0.8 Pa·s flows between two parallel plates separated by 5 mm. If the velocity gradient is 100 s⁻¹, what is the shear stress in the fluid?