Quiz #04: Grease Formulation and Lubrication

1. What is the primary thickener used in lithium grease?
A) Calcium
B) Sodium
C) Bentonite
D) Lithium

2. Which of the following is a primary advantage of using polyurea grease?
A) High water resistance
B) High load-carrying capacity
C) Good pumpability at low temperatures
D) Excellent oxidation stability

3. What role does the base oil play in grease formulation?
A) Acts as a carrier for additives
B) Provides the lubricating properties
C) Serves as a thickening agent
D) Enhances color and odor

4. Which of the following properties is most critical for a grease used in high-temperature applications?
A) Low viscosity
B) High melting point
C) High water resistance
D) Good pumpability

5. What does NLGI grade indicate in grease?
A) The thickness of the grease
B) The dropping point of the grease
C) The load-carrying capacity of the grease
D) The temperature range of the grease

6. Which of the following additives is commonly used to enhance the extreme pressure (EP) properties of grease?
A) Zinc dialkyldithiophosphate (ZDDP)
B) Molybdenum disulfide (MoS2)
C) Calcium sulfonate
D) Silica

7. What is the primary benefit of using synthetic base oils in grease formulation?
A) Lower cost
B) Higher biodegradability
C) Better performance at extreme temperatures
D) Enhanced color stability

8. What is the purpose of a dropping point test in grease analysis?
A) To determine the grease's water resistance
B) To measure the grease's viscosity
C) To identify the temperature at which the grease liquefies
D) To assess the grease's load-carrying capacity

9. Which of the following thickeners provides excellent high-temperature performance and is commonly used in grease formulation?
A) Polyurea
B) Lithium complex
C) Calcium sulfonate
D) Aluminum complex

10. What is one of the main disadvantages of using a grease with a high NLGI grade?
A) Poor high-temperature stability
B) Reduced pumpability
C) Lower load-carrying capacity
D) Higher water solubility