Powder Manufacture
1. Which of the following metal powder is used as a moderator in the atomic energy field?
A. Uranium carbide
B. Beryllium
C. Zirconium and its alloys
D. Thorium
Answer:: B
2. Beryllium is used as a fuel canning material for nuclear reactors.
A. True
B. False
View Answer:
Answer:: A
3. _______ has provided a metal powder designation system, according to which, metal and alloy powders are given a prefix and a four-digit code.
A. ASME
B. ASTM
C. MPIF
D. BIS
Answer:: C
4. Which of the following methods have been developed for the production of complex powders?
A. Atomization and Milling
B. Atomization, Thermal decomposition, Electrolysis, and spray drying
C. Atomization, Thermal decomposition, and Graining
D. Atomization and Electrolysis
Answer:: B
5. Complex alloy powders can be produced by electrolytic deposition method by using _____methods.
A. Electrolyte mixture, anode made of cast alloy, and composite anodes
B. Composite cathodes
C. Composite anodes
D. Electrolyte mixture and composite anodes
View Answer:
Answer:: A
6. Spray drying produces a superalloy powder with dispersed _____
A. Thoria
B. Oxalate
C. Nickel
D. Copper
Answer:: A
7. The alloy F-0000-10 refers to pure fluorine powder with anultimate breaking strength of 10 ksi.
A. True
B. False
View Answer:
Answer:: B
8. In electrodeposition, the final product may be obtained in ____ different forms.
A. 4
B. 3
C. 2
D. 5
Answer:: B
Explanation: In electrodeposition, depending on the processing conditions, the final product may be obtained in 3 different forms. The deposit may be: (1) a hard-brittle layer which is later milled to obtain powder; (2) a soft, spongy substance which is loosely adherent and easily removed by scrubbing; (3) a direct powder deposit from the electrolyte which collects at the bottom of the cell.
9. Ta powder is produced commercially by electrolysis of ______ dissolved in a bath of K2TaF7, KCl, and KF.
A. Tantalum oxide
B. Tantalum sulphate
C. Tantalum chloride
D. Tantalum fluoride
Answer:: A
10. Which of the following factors does not promote powdery deposits?
A. Low temperature
B. High-current-density
C. High-metal concentration
D. High viscosity
Answer:: C
11. Which of the following metal powder is generally not prepared by fused salt electrolysis?
A. Copper
B. Tantalum
C. Vanadium
D. Thorium
Answer:: A
12. Which of the following is not a characteristic of the electrolytic powder deposit?
A. Low apparent density
B. High apparent density
C. Crystalline
D. Dendritic shape
Answer:: B
13. _______ particle shape is obtained for powders produced from hard, brittle deposits.
A. Dendritic
B. Acicular
C. Angular
D. Irregular
Answer:: C
14. _____ is generally added to the iron sulphate or chloride bath to favor high yield of iron powder.
A. NH4Cl
B. KCl
C. K2SO4
D. NH3
Answer:: A
15. _____ is used to calculate theoretical weight deposited on the electrode.
A. Faraday’s law
B. Hess law
C. De-Braggs law
D. Stoke’s law
Answer:: A
16. Time and current are the two important variables which affect the amount of powder deposited on the electrode during electrodeposition of copper.
A. True
B. False
Answer:: A
17. What is the current density when current of 1.5A flows through the electrolytic cell with the cathode plate having an effective length of 46mm, breadth 38mm and negligible thickness?
A. 413.7 A/m2
B. 377.9 A/m2
C. 519.3 A/m2
D. 403.6 A/m2
Answer:: A
18. What is the current efficiency when actual weight deposited is 0.036g and theoretical weight deposited is 0.049g?
A. 73.46%
B. 136.11%
C. 73.12%
D. 88.88%
Answer:: A
19. What is the theoretical amount of copper powder deposited on the cathode plate when a current of 1A passes through the electrolytic tank for 5 minutes?
A. 0.098g
B. 0.0016g
C. 0.190g
D. 0.980g
Answer:: A
20. Which of the following are physicochemical methods of powder production?
A. Thermal decomposition and graining
B. Condensation method and milling
C. Condensation method, gaseous pyrolysis method, and reduction method;
D. Condensation method, gaseous pyrolysis method, reduction method, and cold stream process
Answer:: C
21. The process used on a commercial scale for the production of Ni, Co and Cu powder by the hydrometallurgical method is called _____
A. gaseous Reduction process
B. precipitation from fused salts method
C. oxidation and Decarburization method
D. condensation method
Answer:: A
22. Which of the following is a variant of the hydrometallurgical method?
A. Peace River Process
B. Peace Sea Process
C. Peace Extraction Process
D. Peace Reduction Process
Answer:: A
23. The method employing the principle of precipitating a metal from its aqueous solution by addition of less noble metal (higher in electromotive series) is called _____
A. condensation method
B. gaseous Reduction process
C. precipitation from aqueous solution method
D. precipitation from fused salts method
Answer:: C
24. Which of the following is added to the SnCl2 solution to precipitate Sn?
A. Al
B. Zn
C. Cu
D. Fe
Answer:: B
25. Which of the following is not a characteristic of powder produced by precipitation from an aqueous solution method?
A. Porous in nature
B. High apparent density
C. Low apparent density
D. Difficult to remove the adherent salts
Answer:: B
26. Which of the reducing agent is used for the production of Zn powder by condensation method?
A. CaC2
B. Charcoal
C. CO2
D. H2
Answer:: B
27. Which process is used for the production of pure reactive metal powder, particularly niobium?
A. Intergranular Corrosion process
B. Oxidation and Decarburization method
C. Gaseous Reduction process
D. Reduction method
Answer:: B
28. Mannesmann process employed for the production of Fe powders can be regarded as oxidation and decarburization method.
A. True
B. False
Answer:: A
29. Which of the following method has the principle that grain boundaries are preferential sites for chemical attack than grains?
A. Gaseous Reduction process
B. Hydrometallurgical process
C. Intergranular Corrosion process
D. Oxidation and Decarburization method
Answer:: C
30. Intergranular Corrosion process was used extensively for the production of which of the following powder?
A. Stainless steel
B. Copper
C. Niobium
D. Brass
Answer:: A
31. The adsorption method used for determining the specific surface makes use of which instrument?
A. Fisher Sub-siever
B. BET apparatus
C. Hall Flowmeter
D. Scott Volumeter
Answer:: B
32. The shape factor is given by the ratio of surface area to particle size.
A. True
B. False
Answer:: A
33. Which of the following characteristics does irregular shaped particles do not possess?
A. Reduced apparent density
B. Good pressing properties
C. Good sintering properties
D. Maximum flow rate
Answer:: D
34. Which of the following concepts are used to differentiate and describe particle shapes?
A. Dimensionality of particle
B. Dimensionality and Surface contour
C. Surface contour of particle
D. Dimensionality and atomic mass
Answer:: B
Explanation: Two different concepts used to differentiate and describe particle shapes are based on, (1) the dimensionality of the particle (1D, 2D, 3D., and (2) the surface contour of the particle.
35. Particle shape can be defined as, “the recognized pattern of relationship between points that form the internal surface of the particle.”
A. True
B. False
Answer:: B
36. Which of the following criteria can be used for shape characterization?
A. Verbal expression and evaluation of bulk properties
B. Shape factor
C. Verbal expression, shape factor, and evaluation of bulk properties
D. Shape factor, shape generation, verbal expression, and bulk property evaluation
Answer:: D
37. Which method cannot be used to determine the particle shape?
A. Sieve analysis
B. Optical microscopy
C. SEM
D. TEM
Answer:: A
38. Which of the following particle shape is not produced by the chemical decomposition process of powder manufacture?
A. Acicular
B. Flaky (large and thin plate-like)
C. Rod-like (irregular)
D. Rounded
Answer:: B
39. ______ determines the surface area of powder by measuring the amount of gas adsorbed by a monomolecular layer of the powder.
A. Centrifugal method
B. Gas absorption method
C. Gas adsorption method
D. Permeability method
Answer:: C
40. _____ measures the resistance to fluid flow through a compacted powder bed to calculate the specific surface of the powder.
A. Permeametry
B. Gas adsorption method
C. Elutriation Method
D. Sedimentation method
Answer:: A
