Chemical Engineering - MCQ Practice Questions

A liquid film of thickness δ has a component A diffusing through it with first-order reaction. The Thiele modulus is defined as:

In the penetration theory of mass transfer, the mass transfer coefficient varies with contact time (t) as:

For drying of a wet solid in the constant rate period, the controlling mechanism for mass transfer is:

In a wetted wall column for gas absorption, if the gas film resistance is negligible (R_g ≈ 0), the overall mass transfer coefficient K_g is primarily controlled by:

For the absorption of multiple components from a gas stream into an organic solvent, the selectivity depends on:

In reverse osmosis (RO), the membrane flux equation (Darcy's law for membranes) predicts that flux is:

What is the Biot number (Bi) used to determine in transient heat conduction?

For fully developed laminar flow in a circular pipe with constant wall heat flux, which Nusselt number (Nu) is approximately correct?

In a counter-current heat exchanger with equal heat capacities, what is the maximum possible effectiveness?

The Number of Transfer Units (NTU) is defined as which of the following?

The log mean temperature difference (LMTD) correction factor F is required primarily for which configuration?

For turbulent flow in smooth pipes (Pr > 0.6), which correlation is most commonly used?

In a shell-and-tube heat exchanger (1 shell pass, 2 tube passes), the effectiveness is lower than counter-current primarily because:

For a flat plate solar collector with selective coating, which of the following is most desirable?

For natural convection from a vertical isothermal plate in air, which correlation applies best?

In unsteady-state conduction with Bi << 0.1, what assumption is valid?

In steady-state heat conduction through a composite wall with three layers in series, if the thermal conductivities are k₁ > k₂ > k₃, which layer will have the maximum temperature drop?

For a circular fin of diameter d and length L attached to a surface at temperature T₀, the fin effectiveness approaches zero when:

In forced convection heat transfer, the Colburn factor (j_H) is related to which dimensionless numbers?

In laminar flow through a circular tube with constant wall temperature, the Nusselt number is constant at Nu ≈ 3.66. This means: