Chemical Engineering Basics 1000+ MCQ with answer for CLAT PG

1. Cascade control is
A. The continuous adjustment of the set point index of an automatic control loop by a primary (master) controller
B. Used when changes in process conditions cause serious upsets in the controlled variable
C. Useful to control flow from temperature
D. All 'a', 'b' & 'c'
Answer : D

2. Joule-Thomson co-efficient is the ratio of
A. Pressure change to temperature change occuring during adiabatic compression of a gas
B. Pressure change to temperature change occuring during adiabatic throttling of a gas
C. Temperature change to pressure change occuring during adiabatic compression of a gas
D. Temperature change to pressure change occuring during adiabatic throttling of a gas
Answer : D

3. Addition of small amount of __________ to grey cast iron is done to produce nodular grey cast iron.
A. Manganese
B. Phosphorous
C. Magnesium
D. Chromium
Answer : C

4. The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be
A. Parabolic
B. Hyperbolic
C. Straight line
D. None of these
Answer : A

5. Cassiterite is an ore of
A. Tin
B. Lead
C. Molybdenum
D. Chromium
Answer : A

6. Viscoelastic behaviour is observed in __________ materials.
A. Non-crystalline organic polymeric
B. Ceramic
C. All crystalline
D. All amorphous
Answer : A

7. The swift cup test evaluates the following property of a sheet metal.
A. Stretchability
B. Drawability
C. Bendability
D. None of these
Answer : B

8. Pick out the wrong statement.
A. A ferromagnetic material becomes paramagnetic above the 'Curie temperature'
B. Permanent magnets are made of hard materials, whereas electromagnets require soft magnetic materials
C. Soft magnetic materials (e.g., pure iron) have higher permeability and low hysterisis loss and coercive forces
D. Tungsten steel and alnico are not hard magnetic materials
Answer : D

9. For the Stoke's law to be valid in the case of a falling sphere in a fluid, the
A. Reynolds number (based on sphere diameter) should be < 1
B. Flow around the sphere should be in turbulent region
C. Sphere must be metallic
D. Fluid density should be constant
Answer : C

10. Corrosion rate cannot be lowered by reducing the __________ of the corroding medium.
A. Concentration
B. Velocity
C. Temperature
D. None of these
Answer : A

11. Shrinkage allowance on pattern is provided to compensate for shrinkage when the
A. Metal changes from liquid state to solid state at freezing temperature
B. Solid phase temperature drops from freezing temperature to the room temperature
C. Liquid metal temperature drops from pouring temperature to room temperature
D. Liquid metal temperature drops from pouring temperature to freezing temperature
Answer : B

12. Pick out the correct statement.
A. Materials exhibiting high elasticity obey Hooke's law
B. The elastic behaviour of rubber under compression is the same as its behaviour under tension
C. The damping capacity of a material is due to its plastic deformation
D. The stress required to cause plastic flow in polycrystalline material is higher as compared to monocrystalline materials due to the presence of grains of different orientations
Answer : B

13. Function of fusible plug in a boiler is to
A. Drain out water and sludge from the boiler during repair
B. Put off fire in the furnace when water level in the boiler falls to unsafe limit
C. Guard the boiler in case of abnormal rise in steam pressure
D. All (A), (B) & (C)
Answer : B

14. To counteract the bad effects of strain hardening on a cold formed part, it must be
A. Tempered
B. Normalised
C. Annealed
D. Hardened
Answer : C

15. With increase in temperature, the surface tension of water
A. Increases
B. Decreases
C. Remain constant
D. Increases linearly
Answer : B

16. Starting friction is low in case of the __________ lubrication.
A. Boundary
B. Hydrodynamic
C. Hydrostatic
D. Mixed/semi-fluid
Answer : C

17. The heat released by cooling one mole of copper from 400 K to room temperature (300 K) is (assume : C_p of copper is 23 J K^-1mole^-1)
A. 2300 J
B. 4600 J
C. 230 J
D. 2.3 × 10⁶ J
Answer : A

18. In the acid Bessemer process, the hot metal should have the following composition.
A. S < 0.05% and P < 0.05%
B. S < 0.05% and P < 1.5%
C. S < 0.05% and P > 1.5%
D. S > 1.5% and P < 0.05%
Answer : A

19. What is the value of included angle of a triangular notch for maximum discharge?
A. 30°
B. 60°
C. 90°
D. 120°
Answer : C

20. Normalising does not __________ of a metal.
A. Improve machinability & tensile strength
B. Remove internal stresses
C. Refine the structure
D. Remove strains caused by cold working
Answer : B

21. More than 95% of __________ is present in corundum.
A. SiO₂
B. Al₂O₃
C. CaSiO₂
D. MgO
Answer : B

22. Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its
A. Lower cost
B. Abundant availability
C. Resistance to vegetable acids as the tin plate are commercially used in 'canning' industry
D. None of these
Answer : C

23. Which of the following equipments is used for liquid dispersion?
A. Packed column
B. Venturi scrubber
C. Bubble cap plate column
D. Wetted wall column
Answer : B

24. A thin, flat & square plate measuring 2 m × 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.
A. 50
B. 100
C. 150
D. 200
Answer : B

25. Steel is welded using the __________ flame.
A. Carburising
B. Neutral
C. Oxidising
D. All (A), (B) & (C)
Answer : B

26. Most important property of steels for use in automobile bodies is the
A. Formability
B. Yield strength
C. Toughness
D. Resilience
Answer : A

27. Vernier calipers cannot be used to measure the
A. I.D. & O.D. of the shaft
B. Thickness of parts
C. Depth of holes
D. Clearance between two mating surfaces
Answer : D

28. Air/fuel ratio by weight for combustion of methane with theoretical quantity of air will be about
A. 9 : 1
B. 17 : 1
C. 23 : 1
D. 29 : 1
Answer : B

29. Corrosion is
A. A physical phenomenon
B. A chemical phenomenon
C. Same as erosion
D. An uncontrollable phenomenon
Answer : B

30. Blow off cock is provided in steam boiler to
A. Guard the boiler in case of abnormal rise in steam pressure
B. Drain out water and sludge during its repair
C. Regulate the supply of water in boiler
D. Put out the fire in the furnace when the water level in the boiler falls to unsafe limit
Answer : B

31. Density in the solid state is slightly less than that in its liquid state, in case of
A. Carbon dioxide
B. Water
C. Mercury
D. None of these
Answer : B

32. Eutectoid composition of carbon steel at room temperature is
A. Cementite
B. Pearlite
C. Martensite
D. Ferrite
Answer : B

33. Stresses encountered in the metal forming processes are less than the __________ of the material.
A. Fracture strength
B. Yield strength
C. Elastic limit
D. Limit of proportionality
Answer : A

34. The property of material, by which a given amount of energy is absorbed by it, without plastic deformation, is called
A. Resilience
B. Toughness
C. Ductility
D. Impact strength
Answer : A

35. X-rays are
A. Positively charged
B. Negatively charged
C. Neutral
D. Of higher wavelength than visible light
Answer : C

36. Brazing filler metal used for joining steel plates
A. Melts below the melting points of base metals
B. Melts below 300°C
C. Is copper phosphorous alloy
D. Is copper
Answer : A

37. Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of __________ gms of zinc per of steel strip.
A. 5-10
B. 1000-1500
C. 120-500
D. 1500-3000
Answer : C

38. Which of the following materials does not form adherent oxide film on surface?
A. Copper
B. Nickel
C. Aluminium
D. Gold & silver
Answer : D

39. Biological shield in a nuclear reactor is generally provided to protect against the
A. ?-rays
B. ?-rays
C. Gamma rays & neutrons
D. Electrons
Answer : C

40. Which of the following is prone to cup and cone fracture?
A. Cast iron
B. Soft brass
C. Round specimen of ductile metal
D. Flat tensile specimen of ductile metal
Answer : C

41. Melting point & boiling points of liquid oxygen are respectively - 218.8°C & - 183°C, while the same for liquid nitrogen is - 210°C & - 195.8°C respectively. The difference in melting points of liquid oxygen & liquid nitrogen is not equal to 8.8
A. °C
B. °F
C. °K
D. °R
Answer : B

42. Silicon percentage in the silicon steel used for electrical appliances/equipments is
A. 0.3-0.4
B. 12-14
C. 3-4
D. 20-25
Answer : C

43. An atom bomb works on the principle of
A. Nuclear fission
B. Nuclear fusion
C. Both the nuclear fission & fusion
D. Ionisation
Answer : A

44. What is the pH of distilled water?
A. 0
B. 1
C. 7
D. 14
Answer : C

45. The majority charge carriers in p-type silicon are
A. Free electrons
B. Ions
C. Conduction electrons
D. Holes
Answer : D

46. Which of the following does not have a sharp melting point?
A. Thoria
B. Glass
C. Ice
D. Pig iron
Answer : B

47. The best lubricants for a machine working at high temperature & load is
A. Grease
B. Solid lubricant
C. Animal oils
D. Mineral oils
Answer : B

48. Which of the following metals is not subjected to electrolytic refining/purification?
A. Copper
B. Zinc
C. Tin
D. Aluminium
Answer : C

49. Multistage compression of air as compared to single stage compression offers the advantage of
A. Power saving per unit weight of air delivered
B. Moisture elimination in the inter-stage cooler
C. Increased volumetric efficiency
D. All (A), (B) & (C)
Answer : D

50. The starting of a car takes time in winter, because the
A. Octane number of fuel is decreased
B. Fuel supply for ignition is not sufficient
C. Vaporisation of the fuel is decreased
D. Pour point of fuel decreases
Answer : C