⚗️ Chemical Engineering Solved MCQs with Answers

Practice 1920 approved ⚗️ Chemical Engineering questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

1920 solved MCQs

Solidification time of a molten metal in a casting is proportional to (where, V = volume of metal & A = its surface area ; in the casting)Answer: V²/A² Artificial draught produced by a fan in the furnace can be controlled by theAnswer: All (a), (b) and (c). Pick out the wrong statement.Answer: Very fine grain structure is desirable for high temperature creep application of materials. Minimum diameter of the tube used for making water manometer should be __________ mm to avoid a correction for the effect of capillarity.Answer: 6 Regenerators as compared to recuperators for the same dutyAnswer: Involve higher initial cost Which of the following heat treatment processes is used for softening the hardened material ?Answer: Tempering Circulation of gases in furnace is caused by theAnswer: All (a), (b) and (c). During brazing, if the fluxes are entrapped, it results in theAnswer: Corrosion. Maximum heat dissipation occurs from a steel wire (k = 0.5 W/m. k) of 15 mm diameter exposed to air (h = 20W/m² .k), when the insulation thickness is __________ mm.Answer: 25 Furnace aerodynamics is related to the __________ in the furnace.Answer: Movement of gases All modes of heat transfer i.e., conduction, convection & radiation occur in case of theAnswer: Boiler furnace. If the flame is produced under the hearth and then sweeps up into the heating chamber, this is called a/an __________ furnace.Answer: Underfired The standard instrument used for calibrating the load applied by universal testing machine is calledAnswer: None of these The reductant used in the extraction of magnesium from calcined dolomite via Pidgeon's process isAnswer: Ferro silicon Which is not accomplished in an underfired furnace ?Answer: Increase in heating capacity/m²of floor space. With increase in pressure, the saturation temperature of steamAnswer: Increases rapidly first and then slowly. In practical operation of any furnace, zero oxygen percentage or theoretical CO₂ percentage in flue gas is rarely achieved, because ofAnswer: Imperfect mixing of fuel & air and infiltration of air 'Sterilised zone' around a hazardous chemical industry is an area with __________ km radius around it, in which the total population/inhabitants should be less than 20000 preferably in the upwind direction.Answer: 5 Pick out the wrong statement. Termination of polymerisation reaction occurs, if theAnswer: Catalyst supply is stopped. Rate of heat release in a furnace, which is the measure of heat intensity is defined asAnswer: Kcal/hr/m³combustion space. Oxygen enrichment of combustion air does not result in increase of theAnswer: Oxygen in the flue gas. A thin, flat & square plate measuring 2 m x 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m² . The plate temperature will remain constant at 30°C, if the convective heat transfer co-efficient is __________ W/m2 °C.Answer: 100 The maximum value, which the residual stress in a material can reach is the __________ of the material.Answer: Elastic limit An example of recuperative furnace is theAnswer: Soaking pit Toughness of a material is measured by theAnswer: Universal testing machine. Pick out the wrong statement about nucleate boiling.Answer: The temperature is less than that of film boiling. L.D. (Linz-Donawitz) converter is used in the production ofAnswer: Steel Turning/machining of __________ usually does not require any cutting fluid.Answer: Cast iron Powder metallurgy processing can be used for makingAnswer: Self lubricating bearing and cemented carbide. The moment of inertia of a body comes into play in __________ motion.Answer: Rotational