Use of lubricants increase efficency of machine

Lubrication reduces friction and allows moving machine parts to slide smoothly past each other. Selecting the appropriate lubrication solution can help reduce premature bearing failures and increase machine uptime, productivity and energy efficiency.

Explanation:

c. magnitude and direction

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.