Mechanical Engineering - MCQ Practice Questions

Which of the following fluids is classified as non-Newtonian?

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.

In a pitot tube measurement, the stagnation pressure is 105.5 kPa and static pressure is 100 kPa. What is the velocity of the fluid? (ρ = 1000 kg/m³)

A 300 mm diameter pipe reduces to 150 mm diameter. If velocity in the larger pipe is 1.5 m/s, what is the velocity in the smaller pipe, assuming incompressible flow?

A submerged orifice discharges water under a head of 4 m. The coefficient of discharge is 0.62. If the orifice area is 0.01 m², what is the discharge rate?

For laminar flow in a circular pipe, the Hagen-Poiseuille equation gives discharge as Q = πΔPd⁴/(128μL). This is valid for Reynolds number:

A pump delivers 0.05 m³/s of water against a head of 25 m. If the pump efficiency is 80%, what is the required power input?

In a convergent nozzle, which property increases as the flow accelerates?

A turbine receives water at 3.5 m³/s with a head of 45 m. If the turbine efficiency is 85%, what is the power output?

For a weir with discharge Q = C_w × L × H^($\frac{3}{2}$), if the length is doubled and head is halved, the new discharge becomes:

A jet of water with velocity 20 m/s hits a flat plate perpendicularly. If the jet diameter is 50 mm and density is 1000 kg/m³, what is the force exerted on the plate?

Which dimensionless number is used to characterize the relative importance of gravity and inertial forces in open channel flow?

A 100 mm diameter pipe contains a 90° elbow. If water flows at 3 m/s and minor loss coefficient K = 0.9, what is the head loss?

In compressible flow, if Mach number M = 1.2, the flow is classified as:

A vertical pipe of diameter 40 mm has water flowing upward at 2.5 m/s. If the friction factor is 0.035 and pipe length is 50 m, what is the total head loss (friction + elevation)?

A circular jet impinges on a 45° inclined flat plate and splits equally. If jet velocity is 15 m/s and diameter is 30 mm, what is the magnitude of the resultant force?

In a venturi meter, if the area ratio is 4:1 and the pressure difference is 8 kPa, what is the velocity in the throat? (ρ_water = 1000 kg/m³)

A horizontal jet of 0.02 m² cross-section with velocity 8 m/s strikes a curved vane and is deflected 60°. What is the force on the vane in the direction of jet?

For a rectangular open channel with width 5 m carrying 12 m³/s of water, if the critical depth is 1.5 m, what is the critical velocity?

In fluid mechanics, which of the following statements about Pascal's law is correct?