The thickness of the lubricant film in the boundary  lubrication is about __________.a.15–25 Åb.20–30 Åc.10–20 Å

In boundary lubrication, the lubricant film thickness is critical for reducing friction and wear between surfaces. The typical thickness of the lubricant film in this scenario ranges quite specifically within certain angstroms.

• Option a suggests a thickness of 15–25 Å.
• Option b suggests a thickness of 20–30 Å.
• Option c suggests a thickness of 10–20 Å.

Research and industry standards often indicate that the average thickness of the lubricant film in boundary lubrication tends to fall within the 10–30 Å range, depending on various factors like pressure, temperature, and the types of materials involved.

Looking at the options given, option a (15–25 Å) is generally considered to be the most commonly accepted range in many engineering and lubrication contexts. This is because it captures the typical film thickness when effective lubrication is achieved but prevent metal-to-metal contact.

Final Answer

The thickness of the lubricant film in boundary lubrication is about 15–25 Å.