Mechanical Engineering - MCQ Practice Questions

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 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?

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?

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?

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?

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?

The Reynolds number is defined as Re = ρVD/μ. For water flow in a 25 mm diameter pipe at 2 m/s, if kinematic viscosity ν = 10⁻⁶ m²/s, the flow regime is:

In a manometer, if the pressure difference between two points is measured as 500 mm of mercury column, the equivalent pressure in Pascal is: (Take ρ_mercury = 13,600 kg/m³, g = 9.81 m/s²)

For laminar flow between parallel plates, the velocity profile is parabolic. The average velocity is what fraction of the maximum velocity?

Which of the following is a characteristic of turbulent flow in pipes?

The Darcy-Weisbach equation relates friction loss to: hf = f(L/D)(V²/2g). For a smooth pipe at Re = 1,00,000, the friction factor f is approximately:

A pitot tube measures the stagnation pressure of a flowing fluid. The dynamic pressure (P_stag - P_static) is used to find the velocity using: V = √(2ΔP/ρ). For air flow (ρ = 1.2 kg/m³) with pressure difference of 50 Pa, the velocity is:

In a siphon, the maximum theoretical height to which liquid can be lifted is limited by atmospheric pressure. For water at sea level (P_atm = 101.325 kPa), the theoretical maximum siphon height is:

A submerged gate in a canal discharges water at the bottom. The discharge through the gate is given by Q = Cd × A × √(2g(h₁-h₂)), where Cd is discharge coefficient, A is gate area, and (h₁-h₂) is head difference. Typical value of Cd for a sharp-edged gate is:

The Froude number Fr = V/√(gD) for channel flow determines the flow type. For Fr = 0.8, the flow is classified as: