Machinery Lubrication Technician Certification
(MLA Level 2) Questions With Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
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1. Which lubrication regime occurs when two surfaces are completely
separated by a full film of lubricant?
A. Boundary lubrication
B. Mixed lubrication
C. Hydrodynamic lubrication
D. Solid lubrication
Answer: C
Rationale: Hydrodynamic lubrication occurs when a full fluid film fully
separates moving surfaces, preventing metal-to-metal contact.
2. The primary purpose of viscosity in lubricating oil is to:
A. Improve color stability
B. Resist flow and maintain film strength
C. Increase acidity
,D. Reduce flash point
Answer: B
Rationale: Viscosity defines the oil’s resistance to flow and its ability to
maintain an adequate lubricating film.
3. What is the most common cause of lubricant degradation?
A. Magnetic fields
B. Contamination and oxidation
C. Low pressure
D. High RPM alone
Answer: B
Rationale: Contamination and oxidation are the primary drivers of
lubricant breakdown in machinery.
4. Which additive improves resistance to oxidation?
A. Detergents
B. Anti-wear agents
C. Antioxidants
D. Viscosity index improvers
Answer: C
,Rationale: Antioxidants slow down oxidation reactions, extending
lubricant life.
5. What is the primary function of a grease thickener?
A. Reduce viscosity
B. Suspend oil and give structure
C. Increase acidity
D. Remove contaminants
Answer: B
Rationale: Thickener holds the base oil in place, giving grease its semi-
solid structure.
6. Which contamination type is most damaging to bearings?
A. Water
B. Air
C. Solid particles
D. Heat
Answer: C
Rationale: Solid particles cause abrasive wear and surface fatigue in
bearings.
, 7. ISO cleanliness codes are used to measure:
A. Oil viscosity
B. Particle contamination levels
C. Additive concentration
D. Oil color
Answer: B
Rationale: ISO codes classify the level of particulate contamination in
lubricants.
8. Which bearing type requires the cleanest lubrication environment?
A. Plain bearings
B. Roller bearings
C. Sleeve bearings
D. Journal bearings
Answer: B
Rationale: Rolling element bearings are highly sensitive to
contamination.
9. Viscosity Index (VI) measures oil’s:
A. Density
B. Change in viscosity with temperature
(MLA Level 2) Questions With Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. Which lubrication regime occurs when two surfaces are completely
separated by a full film of lubricant?
A. Boundary lubrication
B. Mixed lubrication
C. Hydrodynamic lubrication
D. Solid lubrication
Answer: C
Rationale: Hydrodynamic lubrication occurs when a full fluid film fully
separates moving surfaces, preventing metal-to-metal contact.
2. The primary purpose of viscosity in lubricating oil is to:
A. Improve color stability
B. Resist flow and maintain film strength
C. Increase acidity
,D. Reduce flash point
Answer: B
Rationale: Viscosity defines the oil’s resistance to flow and its ability to
maintain an adequate lubricating film.
3. What is the most common cause of lubricant degradation?
A. Magnetic fields
B. Contamination and oxidation
C. Low pressure
D. High RPM alone
Answer: B
Rationale: Contamination and oxidation are the primary drivers of
lubricant breakdown in machinery.
4. Which additive improves resistance to oxidation?
A. Detergents
B. Anti-wear agents
C. Antioxidants
D. Viscosity index improvers
Answer: C
,Rationale: Antioxidants slow down oxidation reactions, extending
lubricant life.
5. What is the primary function of a grease thickener?
A. Reduce viscosity
B. Suspend oil and give structure
C. Increase acidity
D. Remove contaminants
Answer: B
Rationale: Thickener holds the base oil in place, giving grease its semi-
solid structure.
6. Which contamination type is most damaging to bearings?
A. Water
B. Air
C. Solid particles
D. Heat
Answer: C
Rationale: Solid particles cause abrasive wear and surface fatigue in
bearings.
, 7. ISO cleanliness codes are used to measure:
A. Oil viscosity
B. Particle contamination levels
C. Additive concentration
D. Oil color
Answer: B
Rationale: ISO codes classify the level of particulate contamination in
lubricants.
8. Which bearing type requires the cleanest lubrication environment?
A. Plain bearings
B. Roller bearings
C. Sleeve bearings
D. Journal bearings
Answer: B
Rationale: Rolling element bearings are highly sensitive to
contamination.
9. Viscosity Index (VI) measures oil’s:
A. Density
B. Change in viscosity with temperature
