SSC CHSL - Chemical Engineering Basics 1000+ MCQ [Solved] PDF Download

1. In chemical dehumidification process
A. Wet bulb temperature increases
B. Dry bulb temperature remains constant
C. Dew point temperature increases
D. Dry bulb temperature increases
Answer : B

2. On decreasing the grain size of a polycrystalline material, the property most likely to deteriorate is
A. Creep
B. Toughness
C. Tensile strength
D. Fatigue
Answer : B

3. Insulation of liquid surface can be achieved by __________ on top of its surface.
A. Floating hollow polypropylene spheres
B. Spraying alumina powder
C. Putting cement
D. None of these
Answer : A

4. In __________ process, there is an increase in entropy with no degradation of energy.
A. Isothermal expansion
B. Isochoric heat addition
C. Polytropic expansion
D. Isobaric heat addition
Answer : A

5. What is the percentage of chromium in 18-4-1 high speed steel?
A. 1
B. 4
C. 18
D. 23
Answer : C

6. A pycnometer is used for the measurement of
A. Flow rate of molten metal
B. Specific gravity of a liquid
C. Composition of alloys
D. Concentration of a solution
Answer : B

7. Hot & cold working of material causes its __________ deformation.
A. Visco-elastic
B. Isotropic
C. Elastic
D. Plastic
Answer : D

8. Which of the following is the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water)?
A. Aluminium
B. Copper
C. Titanium
D. Stainless steel
Answer : C

9. Pick out the wrong statement.
A. Cold cracking of a weld is due to the presence of hydrogen gas in the weld
B. True stress is given by, ? = ?E (1 + ?E), where ?E and ?E are engineering stress and engineering strain respectively
C. Phosphorous can be easily recovered in the iron blast furnace
D. High residual stress at the surface is beneficial for fatigue properties of a material
Answer : C

10. Pick out the wrong statement
A. Processing of thermosetting plastics is ideally done by injection moulding
B. Processing of thermoplastics is ideally done by compression moulding
C. Mass production of seamless pipes are done by electrical resistance welding (ERW)
D. Stretch forming is a process of cold drawing
Answer : C

11. About __________ ton of coke is required in a cupola to produce one ton of casting.
A. 0.03
B. 0.3
C. 0.8
D. 1.5
Answer : B

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

13. Vibration upto 100 kilo hertz can be most accurately measured by a __________ type accelerometer.
A. Preloaded spring
B. Piezoelectric
C. Bonded strain gauge
D. None of these
Answer : B

14. 'Ice point' is designated on Fahrenheit temperature scale by
A. 0°
B. 32°
C. 62°
D. 212°
Answer : B

15. Ferromagnetic materials owe their properties to __________ inner sub-shells.
A. Completely filled
B. Partially filled
C. Equally filled
D. Vacant
Answer : B

16. Solute atoms which cause yield point phenomenon in mild steel are/is
A. Aluminium
B. Boron
C. Carbon
D. Nitrogen
Answer : C

17. Thermit welding uses the following energy source.
A. Electrical energy
B. Chemical energy
C. Energy of high velocity electrons
D. Heat generated by friction
Answer : B

18. Closeness of packing is maximum in case of __________ crystal lattice.
A. Face centred
B. Simple cubic
C. Body centred
D. None of these
Answer : A

19. Square steel key is normally strong in failure by shear & crushing. Keys are normally made of __________ steel bars.
A. Hot rolled mild
B. Cold rolled mild
C. Forged
D. Machinable stainless
Answer : B

20. A material in which the atoms are arranged regularly in some directions but not in others, is termed as 'mesomorphous material'; an example of which is
A. Lead
B. Glass
C. Mica
D. Silver
Answer : A

21. Dew point temperature always gives an indication of the __________ of the moist air.
A. Dryness
B. Moisture content
C. Coolness
D. Latent heat
Answer : B

22. Which one is neutral in character?
A. N₂O₄
B. N₂O
C. N₂O₅
D. N₂O₃
Answer : B

23. The material used for coating the welding electrode is termed as the
A. Flux
B. Slag
C. Protective layer
D. Binder
Answer : B

24. Maximum permissible air velocity in pipelines is about __________ metre/second.
A. 5
B. 10
C. 20
D. 40
Answer : B

25. For an ideal gas, C_p - C_v is
A. R
B. -R
C. 0
D. (3/2) R
Answer : A

26. Wrought iron does not have
A. Uniform strength in all directions
B. Ability to hold protective coating
C. High ductility & corrosion resistance
D. Easily weldable characteristics
Answer : A

27. Which of the following is the correct nature of shear stress distribution along the cross section in a horizontal circular pipe under steady state fluid flow condition?
A.
B.
C.
D.
Answer : C

28. In troposphere (the weather domain), the temperature 't' at height 'h' above the sea level in metres is given by (where, temperature at sea level is 15°C and t is in °C.)
A. t = 15 - 0.0065 h
B. t = 15 + 0.0065 h
C. t = 0.0035 h - 15
D. t = 15 - 0.0035 h
Answer : A

29. 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

30. Stainless steel is welded with difficulty because of
A. Its high melting temperature
B. Chances of cracking
C. Oxide film formation
D. Chromium carbide formation
Answer : C

31. Iron content in Indian iron ore is about __________ percent.
A. 80-85
B. 60-65
C. 40-45
D. 20-25
Answer : B

32. Brinell Hardness Number (BHN) for talc is approximately in the range of
A. 1-5
B. 20-30
C. 100-150
D. 200-250
Answer : B

33. The behaviour of a metal specimen, which when plastically strained in tension reduces its yield stress in compression and vice versa; is termed as the
A. Work hardening
B. Bauschinger effect
C. Creeping effect
D. Stress recovery effect
Answer : B

34. For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm³) while the C.V. is same on weight basis (i.e., kcal/kg)?
A. Propane and acetylene
B. Propane and LPG
C. Sewage gas and gobar gas
D. B.F gas and coke oven gas
Answer : D

35. The surface tension of a liquid, at critical temperature is
A. Indeterminate
B. Zero
C. Infinity
D. Same as that at any other temperature
Answer : B

36. In case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is
A. More
B. Less
C. Equal
D. Much more
Answer : C

37. 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

38. A polymer is termed as an 'elastomer', if its percentage elongation is more than 100%. An elastomer is termed as 'rubber' if its percentage elongation is more than __________ percent.
A. 150
B. 200
C. 300
D. 400
Answer : B

39. Which of the following mainly decides the current to be employed is arc welding?
A. Electrode size
B. Plate thickness
C. Voltage across the arc
D. Welded portion length
Answer : A

40. The joint for soldering is supported by binding wire made of
A. Mild steel
B. Copper
C. Soft iron
D. Stainless steel
Answer : C

41. Cold cracking in the heat affected zone of a high strength steel weld can take place because of the
A. Retained austenite
B. Martensite formation
C. Relatively high sulphur content in the base metal
D. Sufficient hydrogen present in the welding arc
Answer : B

42. While the bin cards are used in the effective stores management, the queuing theory is associated with the __________ time.
A. Waiting
B. Idle
C. Inspection
D. Tool replacement
Answer : A

43. Upto the critical radius of insulation, added insulation, will
A. Increase the heat loss
B. Decrease heat loss and will have no effect beyond that
C. Decrease heat flux
D. Reduce convection heat loss compared to conduction heat less
Answer : B

44. Maraging steels derive their strength from the following mechanism:
A. A fine, highly dislocated and strong martensite
B. Fine dispersions of inter-metallic of Fe, Ni, Ti etc
C. Fine dispersions of alloy carbides in a ferrite matrix
D. Fine dispersions of C nucleated on dislocations in austenite
Answer : A

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

46. Water-tube boiler is the one, in which
A. Water passes through tubes and flue gases around it
B. Tube carrying hot flue gases are immersed in a pool of water
C. Tubes are placed in vertical position
D. None of these
Answer : A

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

48. 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

49. Latent heat of dry steam at atmospheric pressure is 539 Kcal/kg; which __________ with increase in the pressure of steam.
A. Decreases
B. Increases
C. Remain same
D. May increase or decrease
Answer : A

50. Pick out the wrong conversion of absolute & kinematic viscosities.
A. 1 stoke = 1 cm²/sec
B. 1 N.sec/m² = 10 paise
C. 1 stoke = 1 m²/sec
D. 1 m²/sec = 10⁴ stokes
Answer : C