1000+ Chemical Engineering Basics MCQ for DRDO [Solved]

1. Which of the following material handling equipments is not suitable for moving materials in varying paths?
A. Hand trolley
B. Belt conveyor
C. Crane
D. Truck
Answer : B

2. The heat of neutralisation remains constant, when there is a reaction between dilute solutions of strong
A. Base and strong acid
B. Base and weak acid
C. Acid and weak base
D. None of these
Answer : A

3. Which of the following is used to produce draught in the locomotive boilers?
A. Chimney
B. Induced draught fan
C. Forced draught fan
D. Steam jet arrangement
Answer : D

4. 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

5. Referring to the periodic table of elements, it is found that with increasing atomic number. The atomic size in the same
A. Period increases
B. Period decreases
C. Group increases
D. Both 'b' & 'c'
Answer : D

6. What is the value of entropy at 273°K?
A. 0
B. 1
C. ?
D. None of these
Answer : A

7. __________ of air does not increase with increase in temperature.
A. Density
B. Thermal diffusivity
C. Viscosity
D. Thermal conductivity
Answer : A

8. Hydro-cyclone is a
A. Crusher
B. wet classifier
C. Dry classifier
D. Magnetic separator
Answer : B

9. 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

10. The maximum thickness of the metal which can be welded using ultrasonic welding is __________ mm.
A. 0.5
B. 3
C. 10
D. 25
Answer : B

11. 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

12. The wet bulb temperature is lower in dry air than in wet air at the same temperature. A dry bulb thermometer registers a higher temperature than a wet bulb thermometer except at __________ percent relative humidity.
A. 0
B. 100
C. 50
D. None of these
Answer : B

13. Maximum permissible sulphur content in steel is __________ percent.
A. 0.015
B. 0.055
C. 0.505
D. 0.805
Answer : A

14. The same volume of all gases is representative of their
A. Specific gravities
B. Densities
C. Gas characteristic constants
D. Molecular weights
Answer : D

15. Larger length & diameter water pipes are made by
A. Electrical resistance welding
B. Die casting
C. Semi-centrifugal casting
D. Continuous casting
Answer : C

16. For preparation of porous bearings by powder metallurgy, preferred particle shape is
A. Spherical
B. Nodular
C. Irregular
D. No preferred shape
Answer : A

17. Velocity of a gas in sound is not proportional to (where, T = Absolute temperature of the gas. P = Absolute pressure of the gas. y = Ratio of specific heats (Cp/Cv) ? = specific weight of the gas)
A. ?T
B. 1/?P
C. ?y
D. 1/??
Answer : B

18. Atomic __________ is a whole number for an element.
A. Number
B. Weight
C. Radius
D. None of these
Answer : A

19. The ability of tool steel to resist softening at high temperatures is termed as __________ hardness.
A. Red
B. Extended
C. Super
D. Extreme
Answer : C

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

21. 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

22. The burnout heat flux in the nucleate boiling regime is not a function of the
A. Liquid density
B. Vapour density
C. Temperature difference
D. Heat of evaporation
Answer : B

23. 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 meal
Answer : A

24. __________ stress cannot be sustained by a fluid in equilibrium.
A. Shear
B. Tensile
C. Compressive
D. None of these
Answer : A

25. __________ is not a case hardening process.
A. Carburising
B. Nitriding
C. Cyaniding
D. Annealing
Answer : A

26. Optical activity is a/an __________ property.
A. Additive
B. Constitutive
C. Both (A) & (B)
D. Neither (A) nor (B)
Answer : C

27. A particle is settling in a liquid under Stokesian conditions. The free falling velocity of the particle is proportional to
A. ?(Particle diameter)
B. Particle diameter
C. (Particle diameter)²
D. (Particle diameter)³
Answer : B

28. If a nuclear reactor produces more fissile nuclear fuel than it consumes, then it is called a __________ reactor.
A. Critical
B. Breeder
C. Fertile
D. Heterogeneous
Answer : B

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

30. With increase in annealing temperature, the following defect density decreases.
A. Vacancy
B. Dislocation
C. Grain boundary
D. All of these
Answer : D

31. 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

32. Maximum hardenability of steel depends upon its
A. Chemical composition
B. Carbon content
C. Grain size
D. Alloying elements content
Answer : D

33. 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

34. Pick out the wrong statement.
A. Seam welding, projection welding & spot welding are the classification of electrical resistance welding
B. Electrode tip in spot welding is of copper and the tip diameter should be equal to t (where, t = plate thickness to be welded)
C. In spot welding, two pieces to be joined are overlapped and placed between two electrodes
D. Mild steel sheet cannot be spot welded
Answer : D

35. __________ wire is never used for making the heating element.
A. Nichrome
B. Kanthal
C. Invar
D. None of these
Answer : C

36. Specific gravity of hot metal (pig iron) is __________ times that of the blast furnace slag.
A. 2
B. 3
C. 0.8
D. 6
Answer : B

37. The most detrimental impurity in high pressure boiler feed water is
A. Suspended salt
B. Dissolved salt
C. Silica
D. Turbidity
Answer : C

38. Reduction in the grain size reduces the __________ of the material.
A. Fatigue resistance
B. Tensile strength
C. Creep resistance
D. All (A), (B) & (C)
Answer : D

39. In chemical dehumidification of air
A. Both specific humidity & dry bulb temperature increases
B. Both specific humidity & dry bulb temperature decreases
C. Specific humidity decreases & dry bulb temperature increases
D. Specific humidity increases & dry bulb temperature decreases
Answer : C

40. Notched bar test is used for testing the __________ of a material.
A. Impact strength
B. Endurance limit
C. Machinability
D. Corrosion resistance
Answer : A

41. 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

42. 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

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

44. A metal having a Poisson's ratio = 0.3 is elastically deformed under uniaxial tension. If the longitudinal strain = 0.8, then the magnitude of thickness strain is
A. -0.8
B. 0.8
C. +0.08
D. -0.24
Answer : D

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

46. 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

47. With increase in temperature, the electrical conductivity of a __________ decreases.
A. Semi-conductor
B. Metal or alloy
C. Dielectric
D. None of these
Answer : A

48. Speisses is a mixture of the following:
A. Arsenides of heavy metals
B. Antimonides of heavy metals
C. Arsenides & antimonides of heavy metals
D. Iron, cobalt and nickel
Answer : A

49. High speed steel tools retain their hardness upto a temperature of __________ °C.
A. 500
B. 750
C. 900
D. 1100
Answer : C

50. Which of the following fastening devices has its both ends threaded?
A. Bolt
B. Stud
C. Set screw
D. Split nut
Answer : B