21
The elements get oxidised with logarithmic law
A)
Cu, Fe, Zn
B)
Ni, Pb, Al
C)
Cr, Mn, Ti
D)
All are correct
Answer & Solution
Answer: Option
D
22
Which of the following phenomenon that occurs on metal surface during inhibition?
A)
Adsorption only
B)
Adsorption and phase layers
C)
Phase layers only
D)
Neither adsorption nor phase layers
Answer & Solution
Answer: Option
B
23
Match the following:
P. Cathodic protection
1. Decarburisation
Q. Hydrogen attack
2. Erosion
R. Pilling Bedworth ratio
3. Galvanising
S. Cavitation
4. Oxidation of metals
A)
P-3, Q-1, R-4, S-2
B)
P-3, Q-1, R-2, S-4
C)
P-4, Q-2, R-1, S-3
D)
P-4, Q-3, R-2, S-1
Answer & Solution
Answer: Option
A
24
Identify the incorrect statement.
A)
A concentration gradient in the electrolyte may lead to the formation of galvanic cell
B)
Chromium is added to improve the oxidation resistance of stainless steel
C)
Cathodic protection can be provided by applying a coating
D)
A steel bolt or nut is permissible on a large copper vessel
Answer & Solution
Answer: Option
D
25
Match the corrosion phenomenon with the material in which they are commonly observed.
P. Season cracking
1. 70 : 30 brass
Q. Pitting corrosion
2. GI water line fitted with a brass tap
R. Galvanic corrosion
3. Duralumin
S. Caustic embrittlernent
4. Boiler steel
A)
P-1, Q-2, R-3, S-4
B)
P-4, Q-3, R-2, S-1
C)
P-1, Q-2, R-4, S-3
D)
P-3, Q-4, R-1, S-2
Answer & Solution
Answer: Option
A
26
When two metals or alloys are electrically coupled while exposed to an electrolyte is called
A)
uniform corrosion
B)
galvanic corrosion
C)
crevice corrosion
D)
erosion corrosion
Answer & Solution
Answer: Option
B
27
Which is/are the characteristics of the vapor phase inhibitor?
A)
It has a very high vapor pressure
B)
Effective in closed spaces
C)
Inhibit the atmospheric corrosion without being contact with the metal surface
D)
It has very high vapor pressure, inhibit atmosphere corrosion without being contact with the metal surface and very effective in closed spaces
Answer & Solution
Answer: Option
D
A)
A type of corrosion attack (deterioration) uniformly distributed over a metal surface
B)
Corrosion that proceeds at approximately the same rate over a metal surface. Also called general corrosion
C)
Both A and B
D)
None of these
Answer & Solution
Answer: Option
C
29
Which protection method is depicted in then given figure?
A)
Impressed-current supply method
B)
Anodic protection
C)
Sacrificial anode
D)
Anodic protection and sacrificial anode
Answer & Solution
Answer: Option
C
30
The mathematical expression of Faraday's II Law of Electrolysis
A)
m ∝ Q
B)
$$\frac{{{m_1}}}{{{m_2}}} = \frac{{{E_1}}}{{{E_2}}}$$
C)
both A and B
D)
none of these
Answer & Solution
Answer: Option
B
