1000+ Chemical Engineering Basics MCQ for NMAT [Solved]

1. Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of __________ will facilitate the most accurate measurement of the temperature.
A. Copper
B. Steel
C. Aluminium
D. Brass
Answer : A

2. 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

3. Milk is fat dispersed in water. It is an example of
A. Suspension
B. Emulsion
C. Gel
D. Solution
Answer : B

4. Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frother?
A. Cresylic acid
B. Xanthaies
C. Pine oil
D. All 'a' 'b' & 'c'
Answer : B

5. The malleability of a material is the property by virtue of which it can be rolled or hammered into thin sheets. Which of the following materials has the maximum malleability?
A. Lead
B. Copper
C. Aluminium
D. Wrought iron
Answer : A

6. Corona discharge is related to the operation of a/an
A. Induction motor
B. Electrostatic precipitator
C. Fast breeder reactor
D. Magneto hydrodynamic generator (MHD)
Answer : B

7. Recrystallisation temperature of steel is __________ °C.
A. 50
B. 300
C. 500
D. 800
Answer : D

8. Oxide layer formed on the non-ferrous metal surface after its annealing is
A. Removed by acid pickling
B. Hammered into the surface
C. Removed with coarse emery cloth
D. Left as such to protect the surface
Answer : A

9. Liquid nitrogen containers can be made from
A. Ferritic stainless steel
B. HSLA steel
C. Titanium
D. Austenitic stainless steel
Answer : B

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

11. 'Flare tower' used in industry is meant for
A. Venting off (after burning) the excess inflammable/toxic gases at high pressure
B. Absorbing the pollutant gases from the furnace exhaust
C. Cooling of furnace exhaust gases
D. None of these
Answer : A

12. An oxidation process is accompanied with decrease in the
A. Number of electrons
B. Oxidation number
C. Number of ions
D. All (A), (B) & (C)
Answer : A

13. Water flow in the river during flood can be categorised as the __________ flow.
A. Unsteady uniform
B. Unsteady non-uniform
C. Steady uniform
D. Steady non-uniform
Answer : B

14. Which of the following is an ore dressing operation?
A. Classification
B. Smelting
C. Roasting
D. None of these
Answer : A

15. The most important consideration, while designing the refrigeration system of an aircraft is that the refrigeration system
A. Is as light as possible
B. Has very high C.O.P.
C. Employs minimum quantity of refrigerant
D. Consumer minimum horse power
Answer : A

16. As the fluid flow rate increases, the float of the Rotameter
A. Rises in the tube
B. Rotates at higher speed
C. Rotates at lower speed
D. Drops down in the tube
Answer : A

17. Metalloids
A. Are good conductor of heat & electricity
B. Act as electron donors with metals & as electron acceptor with non-metals
C. Are not necessarily solids at room temperature
D. Are compounds that exhibit both metallic & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron
Answer : D

18. Globular form of cementite is formed during the __________ process.
A. Spheroidising
B. Hardening
C. Annealing
D. Normalising
Answer : B

19. Dislocations are __________ defects.
A. Point
B. Line
C. Volume
D. None of these
Answer : B

20. Removal of non-condensable from steam or other vapour is termed as the __________ process.
A. Condensation
B. Deaeration
C. Scavenging
D. Exhaust
Answer : B

21. Metallic surveying tapes are made of __________ which has a low co-efficient of expansion & enough strength.
A. Invar
B. Hastelloy
C. Duralumin
D. Monel metal
Answer : A

22. Which of the following is the most wear resistant grade of carbide used for the cutting tools?
A. Aluminium carbide
B. Tungsten carbide
C. Nickel carbide
D. Iron carbide
Answer : B

23. The co-ordination number in simple cubic structure is
A. 4
B. 6
C. 8
D. 12
Answer : B

24. 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

25. Which of the following metals reacts violently with water?
A. Mercury
B. Sodium
C. Calcium
D. Magnesium
Answer : B

26. The most abundant metal present in the earth's crust is;
A. Iron
B. Copper
C. Titanium
D. Aluminium
Answer : D

27. Water hammer is caused in steam carrying pipelines, because of
A. Partial condensation of steam
B. Vibration of the pipeline
C. High degree of superheat of steam
D. Its exposure to torrential rain
Answer : A

28. Carbon supply in pack carburising process is in the form of
A. Charcoal
B. Calcium carbide
C. Hydrocarbon oil
D. Graphite
Answer : A

29. 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

30. In TIG welding, thoriated tungsten electrodes are used, because it
A. Has higher current carrying capacity
B. Has better electron emissivity
C. Is stronger than ordinary tungsten
D. Is easy to prepare
Answer : B

31. The trace metal present in insulin is
A. Cu
B. Zn
C. Fe
D. Ni
Answer : B

32. Air standard Otto cycle is more efficient than the diesel cycle for the same
A. Heat addition & compression ratio
B. Heat addition & pressure
C. Compression ratio & pressure
D. Cylinder dimension & rpm
Answer : A

33. Which of the following is the most suitable abrasive for grinding high tensile strength materials?
A. Silicon carbide
B. Corundum
C. Aluminium oxide
D. Boron carbide
Answer : C

34. The usual energy consumption in electric arc furnace steel making is __________ KWh/ton of steel.
A. 60 - 100
B. 400 - 700
C. 1200 -1500
D. 2000 - 2300
Answer : B

35. Which of the following is a commonly used manometric liquid for low pressure range?
A. Ethyl alcohol
B. Carbon tetrachloride
C. Glycerol
D. Ethylene glycol
Answer : B

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

37. Pick out the wrong statement.
A. Molecules with symmetrical arrangements (e.g. CH₄ or CCl₄) are non-polar
B. Generally, non-polar compounds are chemically inactive, conduct electricity poorly and do not ionise
C. Most of the hydrocarbons are non-polar
D. None of these
Answer : D

38. Cold working of a material results in increase in hardness, which is termed as the __________ hardening.
A. Cold
B. Work
C. Age
D. Induction
Answer : B

39. High endurance limit of carburised machine parts is because of the fact that carburisation
A. Suppresses any stress concentration produced in the parts
B. Enhances the yield point of the material
C. Introduces a compressive layer on the surface
D. Produces a better surface finish
Answer : C

40. Increase in temperature, in general results in the
A. Decrease in the viscosities of both liquids & gases
B. Increase in the viscosities of both liquids & gases
C. Increase in the viscosity of liquids and decrease in that of gases
D. Decrease in the viscosity of liquids and increase in that of gases
Answer : D

41. The excess air required for the combustion of pulverised coal is of the order of about __________ percent.
A. 5
B. 15
C. 30
D. 45
Answer : B

42. Sudden fall of atmospheric pressure by a large amount is an indication of the
A. Rain
B. Cold wave
C. Storm
D. Fair weather
Answer : C

43. Yield strength of a polycrystalline metal with an average grain size d, is proportional to
A. d^1/2
B. d^-1/2
C. d
D. d^-1
Answer : B

44. Pick out the wrong statement.
A. Lead can creep under its own weight at room temperature
B. The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement
C Recrystallisation temperature decreases with decrease in strain in a cold worked metal
D. With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase
Answer : C

45. Preheating before welding is done to
A. Make the plate softer
B. Burn oil & grease sticking to plate surfaces
C. Avoid plate distortion
D. Prevent cold cracks
Answer : D

46. Fog is an example of colloidal system of
A. Solid dispersed in gas
B. Solid dispersed in liquid
C. Liquid dispersed in gas
D. Gas dispersed in liquid
Answer : C

47. Dryness factor of steam is defined as the ratio of the mass of vapor in the mixture to the mass of the mixture. Dryness factor of steam is measured by a __________ calorimeter.
A. Bomb
B. Throttling
C. Junker's
D. Boy's
Answer : B

48. Rankine cycle comprises of two isothermal and two __________ processes.
A. Isobaric
B. Polytropic
C. Isentropic
D. None of these
Answer : D

49. The dimensional formula of bulk modulus of elasticity is same as that of the
A. Pressure
B. Density
C. Force
D. None of these
Answer : A

50. Which of the following is not an explosive?
A. TNT
B. CMC
C. RDX
D. Lead azide
Answer : B