Chemical Engineering Basics 1000+ MCQ with answer for SSC JE

1. The mechanism which changes the value of manipulated variable in response to the output signal from the control unit is called the
A. Final control element
B. On-off control
C. Floating control action
D. None of these
Answer : A

2. Increasing sulphur content in pig iron tends to make it
A. Soft
B. Hard
C. Tough
D. Ductile & malleable
Answer : B

3. Constituents of stellite are
A. Zinc, copper & nickel
B. Cobalt, chromium & tungsten
C. Zinc, aluminium & nickel
D. Nickel, cobalt & vanadium
Answer : B

4. Thermal efficiency of an internal combustion engine is around __________ percent.
A. 8
B. 35
C. 65
D. 80
Answer : B

5. A jet engine turbine blade is normally manufactured by
A. Forging
B. Shell moulding
C. Investment casting
D. Pressure die casting
Answer : C

6. A solid aluminium ball, when quenched in a water bath maintained at 40°C, cools down from 550°C to 450°C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about __________ °C.
A. 370
B. 340
C. 320
D. 300
Answer : A

7. The following type of bonding is strongly directional in solids.
A. Vander Waal's
B. Ionic
C. Metallic
D. Covalent
Answer : D

8. Steel & cast iron pipes are produced by __________ casting.
A. Slush
B. Die
C. Investment
D. True centrifugal
Answer : D

9. Annealing of cast iron
A. Softens it to facilitate machining
B. Decreases the free carbon
C. Increases the strength
D. None of these
Answer : A

10. Which of the following approaches the ideal gas behaviour most closely?
A. Wet steam
B. Saturated steam
C. Superheated steam
D. Saturated water
Answer : C

11. Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of
A. 90% tungsten carbide and 10% cobalt
B. 70% aluminium oxide & 30% silica
C. 30% nickel, 15% chromium & 55% tungsten
D. 65% tungsten & 35% zirconium
Answer : A

12. Consumable electrodes are used in the __________ welding.
A. Gas
B. Arc
C. Thermit
D. Resistance
Answer : B

13. __________ joint is usually used for joining cast iron pipes mostly used for temporary pipelines, where it may be necessary to dismantle & reassemble the pipeline very frequently.
A. Collar
B. Flanged
C. Bell and Spigot
D. Expansion
Answer : B

14. Basicity of the slag in Indian blast furnace is in the range of
A. 0.7-1.0
B. 1.1-1.4
C. 1.5 - 1.8
D. 2.0 - 2.5
Answer : B

15. Which of the following does not discharge the dust collected as a dry solid?
A. Electrostatic precipitator
B. Wet scrubber
C. Bag filter
D. Gravity settling chamber
Answer : B

16. Minimum thermal efficiency of a steam boiler may be around __________ percent
A. 25
B. 45
C. 65
D. 20
Answer : D

17. Which of the following is not an ore of copper?
A. Cryolite
B. Azurite
C. Chalcopyrite
D. Malachite
Answer : A

18. The substance used as a smoke screen in warfare is
A. C2H2
B. SiCl4
C. P2O5
D. PCl5
Answer : B

19. In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C.
A. 20
B. 60
C. 120
D. ?
Answer : D

20. Basic open hearth furnace (BOF) is not used for producing __________ steel.
A. Killed
B. Rimming
C. High alloy
D. None of these
Answer : C

21. For grinding of softer materials, the grinding wheel should have __________ grain size.
A. Finer
B. Coarser
C. Medium
D. Any type of
Answer : B

22. The value of for air & most common gases can be safely assumed to be
A. 0.8
B. 1
C. 1.4
D. 1.8
Answer : C

23. Plants produce carbohydrates from the CO2 present in the atmosphere by
A. Polymerisation
B. Photochemical reaction
C. Oxidation
D. None of these
Answer : B

24. Spheroidising of a material is a/an __________ process.
A. Normalising
B. Annealing
C. Tempering
D. Hardening
Answer : B

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

26. Alcohols are not suitable as diesel engine fuel because the cetane number of alcohols is
A. Very low which prevents their ignition by compression
B. Very high which prevents their ignition by compression
C. Zero
D. None of these
Answer : A

27. Which of the following metals cannot be hot worked at room temperature?
A. Zinc
B. Nickel
C. Lead
D. Tin
Answer : B

28. The refractory lining of the bottom in a basic electric arc furnace is made of
A. Silica
B. Alumina
C. Magnesia
D. Fireclay
Answer : C

29. According to maximum shear stress failure criterion, yielding in material occurs, when the maximum shear stress is equal to __________ times the yield stress.
A. 0.5
B. 2
C. ?2
D. ?3/2
Answer : A

30. Materials having __________ lattice structure are usually the most ductile.
A. Body centred cubic (bcc)
B. Hexagonal close packed (hcp)
C. Face centred cubic (fcc)
D. None of these
Answer : C

31. The rolling process cannot be used to produce
A. Plates
B. Rods
C. Tubes
D. Wires
Answer : C

32. The most serious manufacturing defect from fracture toughness point of view is
A. Surface roughness
B. Pores
C. Spherical inclusion
D. Crack
Answer : D

33. Thermal conductivity of a material does not depend upon its
A. Mass
B. Volume
C. Surface area
D. All 'a', 'b' & 'c'
Answer : D

34. Saturated steam at a pressure of 25 kg/cm² is throttled to attain 5 kg/cm². Then the outcoming steam will be
A. Wet
B. Saturated
C. Superheated
D. None of these
Answer : C

35. __________ iron is produced by the annealing of white cast iron.
A. Malleable
B. Nodular
C. Ductile
D. Grey
Answer : A

36. Resilience of a bolt can be increased by increasing its
A. Length
B. Shank diameter
C. Head diameter
D. None of these
Answer : A

37. Which of the following is not a dielectric material?
A. Cotton, silk and paper
B. Asbestos, glass, porcelain and mica
C. Rubber and polymeric resins
D. All refractory materials
Answer : C

38. Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50% B is
A. R ln 2
B. -R ln 2
C. 3 R ln 2
D. -3R ln 2
Answer : A

39. A spring material should have low
A. Elastic limit
B. Deflection value
C. Fatigue resistance
D. None of these
Answer : D

40. __________ test can be termed as the semidestructive test.
A. Impact
B. Torsion
C. Hardness
D. Charpy
Answer : C

41. In the blast furnace, incorporation of water vapour in the blast gives the following effect.
A. Increases the reducing potential of the gas
B. Increases the flame temperature
C. No significant change occurs
D. Increases the hydrogen content in the metal
Answer : A

42. Fire in fuel gas pipelines is extinguished most effectively by
A. Spraying water
B. Blanketting the area with nitrogen atmosphere
C. Fire fighting foam
D. None of these
Answer : B

43. 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

44. The kinematic viscosity (in stoke) and the absolute/dynamic viscosity (in poise) are the same for __________ at room temperature.
A. Air
B. Water
C. Mercury
D. Alcohol
Answer : B

45. If the head is doubled in & centrifugal pump, the power required will increase in the ratio of
A. 2³
B. 2^3/2
C. 2^5/2
D. 2^1/3
Answer : B

46. In a neutral solution
A. H⁺ ions are absent
B. OH^- ions are absent
C. Both H⁺ and OH^- ions are present in very small but equal concentration
D. None of these
Answer : C

47. Spark plug is provided in a/an
A. Engine having carburettor
B. Diesel engine
C. Compression ignition engine
D. Both (B) & (C)
Answer : A

48. The emf of a Deniell cell Zn | Zn²⁺ || Cu²⁺ | Cu can be increased by
A. Decreasing the surface area of the electrodes
B. Increasing the concentration of zinc sulphate solution
C. Increasing the surface area of the electrodes
D. Increasing the concentration of copper sulphate solution
Answer : D

49. __________ property of a material is determined by the Herbert Pendulum device.
A. Hardness
B. Tensile
C. Toughness
D. Compressive
Answer : A

50. A psychrometer does not measure the __________ temperature of moist air.
A. Dew point
B. Dry bulb
C. Wet bulb
D. None of these
Answer : A