Chemical Engineering Basics for Interview pdf - Set 09 - ObjectiveBooks

Chemical Engineering Basics for Interview pdf - Set 09

Practice Test: Question Set - 09

1. Between 230 and 370°C, blue brittleness is caused in mild steel because of the
    (A) Immobility of dislocation
    (B) Strain-ageing
    (C) Increase in Young's modulus
    (D) Strain hardening

2. Sub zero treatment of steel is done to
    (A) Suppress martensite transformation
    (B) Enhance its working performance in sub zero atmosphere
    (C) Reduce the retained austenite in hardened steel
    (D) Induce temper brittleness after its hardening

3. The units of the rate constant for a second order reaction are
    (A) Sec-1. mole°
    (B) Moles1. sec-1
    (C) Moles-1. sec1
    (D) Moles1. sec1

4. Pick out the wrong statement about the machinability of metals. Machinability of a metal
    (A) Decreases with increase in strain hardening tendencies
    (B) Decreases with increase in hardness, in general
    (C) Depend on the composition, microstructure and physical & mechanical properties
    (D) Decreases with increases in tensile strength & decrease in grain size

5. The most detrimental impurity in high pressure boiler feed water is
    (A) Suspended salt
    (B) Dissolved salt
    (C) Silica
    (D) Turbidity

6. 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

7. Biological shield in a nuclear reactor is generally provided to protect against the
    (A) α-rays
    (B) β-rays
    (C) Gamma rays & neutrons
    (D) Electrons

8. 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

9. The thickness of oxide film is y at time t. If K1K2 and K3 are the temperature dependent constants, the parabolic law of oxidation is given by
    (A) y2 = 2k1t + k2
    (B) y = k1 ln (k2t + k3)
    (C) y = k1 t + k2
    (D) y = k1t3 + k2

10. Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to _________ boiling.
    (A) Film
    (B) Nucleate
    (C) Transition
    (D) All modes of

11. Plastics as a material of construction suffer from the drawback of low
    (A) Machinability
    (B) Density
    (C) Strength
    (D) Plastic deformation

12. Normalizing does not _________ of a metal.
    (A) Improve machinability & tensile strength
    (B) Remove internal stresses
    (C) Refine the structure
    (D) Remove strains caused by cold working

13. Which of the following is an ore dressing operation?
    (A) Classification
    (B) Smelting
    (C) Roasting
    (D) None of these

14. Material of construction of the electrode used in the electric resistance welding is
    (A) Stainless steel
    (B) Graphite
    (C) Copper
    (D) Steel

15. Shampoos are commercially not available in the form of
    (A) Powder
    (B) Gaseous mixture
    (C) Solution
    (D) Emulsion

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