Chemical Engineering - MCQ Practice Questions

A centrifugal pump operates with water (ρ = 1000 kg/m³) at an impeller diameter of 0.3 m and rotational speed of 1500 RPM. Calculate the peripheral velocity at the impeller tip.

In laminar flow through a circular pipe, the velocity profile is parabolic. What is the ratio of average velocity to maximum velocity at the centerline?

Which dimensionless number characterizes the relative importance of inertial forces to viscous forces in fluid flow?

In turbulent flow through a pipe, the friction factor can be estimated using the Colebrook-White equation. For smooth pipes at high Reynolds numbers, which equation applies?

A fluid flows through a sudden expansion from pipe diameter D₁ = 0.05 m to D₂ = 0.1 m with velocity V₁ = 4 m/s. Calculate the pressure recovery coefficient (Cp) for the expansion.

In an orifice meter with diameter ratio β = 0.6, what is the typical discharge coefficient (Cd) used for flow calculations?

A rotameter (variable area flowmeter) is used for gas flow measurement. The float rise in the tube depends on which factor?

For compressible isothermal flow through a horizontal pipe, which statement is correct?

In a reciprocating pump with piston diameter D = 0.1 m and stroke length L = 0.2 m operating at 60 RPM, calculate the theoretical displacement per revolution.

Which of the following conditions must be satisfied for cavitation to occur in a centrifugal pump?

In open channel flow, the Froude number is defined as Fr = V/√(gD_h), where D_h is the hydraulic depth. When Fr = 1, the flow is classified as:

For flow measurement in a Venturi tube with diameter ratio (D₁/D₂) = 2, what is the diameter ratio for minimum vibration and noise?

A gas flows through a convergent nozzle. At what condition does maximum mass flow rate occur in the nozzle exit?

The Moody diagram is used to determine friction factor in pipes. For which flow regime is the Darcy friction factor independent of Reynolds number?

In boundary layer theory, the displacement thickness (δ*) represents which physical concept?

A fluid with kinematic viscosity ν = 2×10⁻⁵ m²/s flows over a flat plate at velocity V = 10 m/s. At what plate length does transition from laminar to turbulent flow occur (Re_critical ≈ 5×10⁵)?

In a settling tank (clarifier) with depth H = 2 m, overflow rate = 1 m³/m²·h, and settling velocity of particles = 0.02 m/min, will the particles settle completely?

For a centrifugal pump, cavitation can be prevented by maintaining NPSH above the required value. In 2024-25 industrial practice, what is the typical margin kept above calculated NPSH_required?

A submersed weir has crest length L = 1.5 m and head H = 0.6 m. Using Francis formula for suppressed weir (Q = 1.84 LH^1.5), calculate discharge.

In pipe flow with fittings, which fitting typically causes the highest pressure loss coefficient (K)?