Chemical Engineering - MCQ Practice Questions

In pipeline heat loss calculations for process industries, the critical radius of insulation is the thickness at which the outer surface area increase due to added insulation equals the reduction in heat transfer coefficient. For a pipe with outer radius r_o = 50 mm and insulation thermal conductivity k = 0.05 W/(m·K), what is the approximate critical radius?

In the 2024-2025 update to heat exchanger design standards (TEMA), which of the following represents the most significant advancement in fouling prediction for industrial heat exchangers?

A double-pipe heat exchanger (counterflow) is used to cool 5 kg/s of oil (Cp = 2.0 kJ/kg·K) from 80°C to 50°C using water at 20°C entering with a temperature rise of 15°C. What is the water flow rate required?

A 10 cm diameter steel pipe (k = 50 W/m·K) with inner diameter 9 cm carries hot water at 90°C. Outer surface is at 70°C. Calculate heat transfer rate per meter length.

In cross-flow heat exchangers (unmixed-unmixed configuration), the effectiveness is lower than parallel/counterflow because:

For turbulent flow over a flat plate, the local Nusselt number varies with distance x according to which relationship?