Lubrication

Which one of them is a correct combination?

• 1-(i), 2-(iv), 3-(ii), 4-(iii).

• 2-(i), 3-(iv), 4-(iii), 1-(ii).

• 1-(iv), 3-(iii), 2-(i), 4-(ii).

• 3-(iv), 2-(iii), 1-(i), 4-(ii).

The purpose of lubrication is

• To reduce friction.

• Transfer heat produced.

• To reduce wear.

• All of above.

Which of the following is NOT a function of lubricant in IC engine?

• Form a film to separate the surfaces.

• Withstand high temperature inside the cylinder.

• Adhere to surface.

• Reduce the size of the asperities and improve the surface finish.

Tags

NGSS.MS-PS3-4

Synovial fluid is a lubricant that is found in

• Human bone joints.

• IC engines.

• Gearboxes.

• Rolling element bearings.

As the temperature is increased, the coefficient of friction

• Increases.

• Remains unchanged.

• Reduces.

• Increase or decrease based on the lubrication regime.

Which of the following is a desirable property of boundary lubricant?

• Dissolvability in lubricating oils.

• Low shear strength and high melting point.

• Affinity to metallic surfaces.

• All of above.

In hydrodynamic lubrication the major source of friction is

• Shearing of lubricant film.

• Abrasion of tribo-surfaces due to free particles.

• Abrasion due to asperities on tribo-surfaces

• All of the above.

Film thickness in elastohydrodynamic lubrication depends on

• Applied load and relative velocity

• Lubricant properties.

• Properties of contacting materials

• All of above.

What is the primary purpose of lubrication in machinery?

• To reduce friction

• To increase friction

• To cool the machinery

• To increase wear

Which of the following is a common lubricant used in engines?

• Water

• Graphite

• Oil

• Sand