1000+ Chemical Engineering Basics MCQ for SSC JHT [Solved]

1. Electrochemical corrosion can occur, only if __________ is present in contact with metal.
A. Air
B. Oxygen
C. Liquid medium
D. Gaseous medium
Answer : C

2. __________ the exhaust gas is an indication of the incomplete combustion of fuel.
A. Low temperature of
B. High temperature of
C. High % of CO in
D. High % of CO₂ in
Answer : C

3. 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

4. A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution.
A. Neutral
B. Ideal
C. Buffer
D. Zero pH
Answer : C

5. Case hardening of a material is
A. Followed by tempering or carburising
B. Preceded by its tempering
C. Done to get a soft ductile interior with a very hard surface
D. Carried out to get extreme hardness in its core
Answer : D

6. __________ flux is used for the extraction of metal from its self fluxing ores.
A. No
B. Acid
C. Basic
D. Neutral
Answer : A

7. The function of neutral flux used in the pyrometallurgy of metal extraction is to increase the __________ of the slag.
A. Fluidity
B. Basicity
C. Acidity
D. Viscosity
Answer : A

8. Which of the following gases cause global warming?
A. Carbon monoxide
B. Carbon dioxide
C. Nitrogen
D. Ozone
Answer : B

9. Current employed in resistance welding ranges from __________ kVA/.
A. 1.2 to 2.5
B. 4.5 to 6.2
C. 7.5 to 8.5
D. 10.5 to 15.5
Answer : B

10. Joining of thin foils is preferred to be done by
A. Gamma rays
B. X-rays
C. Microwaves
D. Gas welding
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. 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

13. Glycerine is used as a coolant in cooling of some engines instead of water, because
A. Its higher boiling point (290°C) increases its heat carrying capacity
B. Comparatively less weight of coolant is required
C. Smaller radiator can be used
D. All a, b & c
Answer : D

14. Use of flux during soldering is done to
A. Increase fluidity of solder by lowering its melting temperature
B. Prevent oxide formation
C. Wash away surplus solder
D. Full up the joint gap
Answer : B

15. There are one octahedral void and __________ tetrahedral void in the closest packing of atoms.
A. One
B. Two
C. Three
D. None of these
Answer : B

16. The lightest non-inflammable gas is
A. H2
B. He
C. Ar
D. O2
Answer : B

17. Which of the following hardness tests does not measure the indentation hardness of metals and alloys?
A. Vickers hardness test
B. Shore scleroscope test
C. Brinell hardness test
D. Rockwell hardness test
Answer : B

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

19. Lead is poured into the joint between two __________ pipes.
A. Mild steel
B. Concrete
C. Cast iron
D. Asbestos cement
Answer : C

20. A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will
A. Increase
B. Decrease
C. Remain unaffected
D. May increase or decrease; depends on the thickness of each layer
Answer : C

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

22. Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs?
A. Enthalpy
B. Relative humidity
C. Wet bulb temperature
D. Dew point temperature
Answer : D

23. The process of removal of scale formed during hot rolling of steel is termed as
A. Descaling
B. Shot blasting
C. Pickling
D. Skimming
Answer : C

24. Galvanic corrosion cannot be prevented by
A. Cathodic protection
B. Anodic protection
C. Usage of largest possible anodic area
D. Any one of these
Answer : B

25. Two wires of the same radius & material having length in the ratio of 1 : 2 are stretched by the same force. The strain produced in the two wires will be in the ratio of
A. 1 : 1
B. 1 : 2
C. 2 : 1
D. 1 : 4
Answer : A

26. Air-petrol ratio in an automotive petrol engine is around
A. 14 : 1
B. 22 : 1
C. 25 : 1
D. 4 : 1
Answer : A

27. A material is capable of resisting softening at high temperature, because of its property termed as
A. Hot temper
B. Hot hardness
C. Fatigue
D. Creep
Answer : B

28. 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

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

30. Fire refining process is employed in case of
A. Tin
B. Copper
C. Zinc
D. Aluminium
Answer : B

31. Factor of safety is the ratio of the __________ stress to the working stress.
A. Tensile
B. Compressive
C. Yield
D. Bearing
Answer : C

32. Gage pressure within a spherical droplet of a fluid is 'p'. What will be gage pressure within a bubble of the same size & of the same fluid?
A. p
B. 2 p
C. 0.5 p
D. 0.25 p
Answer : B

33. 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

34. Neutrons are present in all atoms except that of
A. He
B. C
C. H
D. Ar
Answer : C

35. High relative humidity decreases the evaporative process and as the temperature is increased, the relative humidity decreases. The comfort range for human body is the ambient temperature of 22 to 27°C with relative humidity ranging from __________ percent.
A. 5 to 10
B. 15 to 25
C. 45 to 50
D. 75 to 80
Answer : C

36. Hydrogen in liquid steels is dissolved
A. As tiny gas bubbles
B. In the atomic form
C. In the ionic form
D. In the molecular form
Answer : A

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

38. Hot working of lead is carried out at
A. 75°C
B. 373°K
C. 150°C
D. Room temperature
Answer : B

39. Which of the following is preferred for riveting?
A. Lap joint
B. Butt joint
C. Either (A) or (B)
D. Neither (A) nor (B)
Answer : B

40. Main constituent of bone ash is
A. Ammonium phosphate
B. Calcium phosphate
C. Animal charcoal
D. Ammonium sulphate
Answer : B

41. A 2 kg object weighs 1.8 kgf on a spring balance. The value of 'g' at that location in m/sec² is
A. 8.82
B. 9.81
C. 10.88
D. 0.95
Answer : A

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

43. 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

44. The condition of diffraction from a crystal is given by
A. n? = 2d Sin ?
B. ? = d Sin 2?
C. ? = 2d Sin 2?
D. n? = d Sin ?
Answer : A

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

46. Use of economiser in a boiler plant reduces the fuel consumption for steam generation by about __________ percent.
A. 1
B. 10
C. 30
D. 50
Answer : B

47. A form of stress corrosion failure termed as 'season cracking' is generally observed in
A. Thermosetting polymers
B. High carbon steels
C. Brasses
D. Borosilicate glasses
Answer : C

48. Which of the following is the largest quantum of pressure?
A. 1 kg/cm²
B. 1 bar
C. 1 atmosphere
D. 1 kilo Pascal
Answer : C

49. Brass parts with high residual tensile stress at the surface are susceptible to season cracking (i.e. spontaneous cracking occuring on exposure to atmospheric corrosion), if its zinc percentage is more than
A. 5
B. 10
C. 20
D. 35
Answer : C

50. __________ fluid force is not considered in the Navier-Stokes equation.
A. Turbulent
B. Viscous
C. Gravity
D. Pressure
Answer : A