Chemical Engineering - MCQ Practice Questions

A pipeline carries water at 20°C. When the flow velocity increases from 1 m/s to 3 m/s in a straight horizontal pipe of constant diameter, the friction factor:

Which of the following best describes the boundary layer separation phenomenon?

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?

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

In a converging-diverging nozzle, if pressure increases in the diverging section, what type of flow pattern occurs?

A vertical cylindrical settling tank has diameter 3 m and height 4 m. For a particle settling velocity of 2 cm/min, what should be the volumetric flow rate to achieve 90% removal efficiency?

A pump operating at 1200 RPM delivers 150 L/s against a head of 40 m. If speed increases to 1800 RPM, what will be the new head (assuming affinity laws apply)?

In computational fluid dynamics (CFD), the Courant number (Co = U×Δt/Δx) is important for numerical stability. For explicit schemes, the Courant number should be:

For a reciprocating pump with bore diameter 0.08 m, stroke length 0.15 m, and operating at 60 RPM with 90% volumetric efficiency, the discharge is approximately:

In a convergent-divergent (de Laval) nozzle for compressible flow, the pressure reaches minimum (maximum acceleration) at:

The Navier-Stokes equation for incompressible flow includes terms for pressure gradient, viscous forces, and inertial forces. Under creeping flow conditions (Re → 0), which term becomes negligible?

What is the activation energy for a reaction if its rate constant doubles when temperature increases from 300K to 310K?

Which reactor configuration gives maximum yield for a series reaction A→B→C where k₁ >> k₂?

For a reaction with E_a = 50 kJ/mol, if temperature is increased from 300K to 400K, by what factor does rate constant increase? (R = 8.314 J/mol·K)

Which approximation is used in steady-state kinetics for enzyme reactions?

For consecutive reactions A→B→C, the concentration of intermediate B is maximum at time t_max. This time depends on:

In desorption-limited catalytic reactions, which step determines the overall reaction rate?

What is the significance of the Thiele modulus (φ) in heterogeneous catalysis?