Describe some events when we reduce the friction.

We sprinkled fine powder on the carom board. When a few drops of oil are poured on the hinges of a door moves smoothly. A cycle or a motor mechanic uses grease between the moving parts of the cycle. In all the above cases, we want to reduce friction in order to increase efficiency. When oil, grease or graphite is applied between the moving part of a machine, its thin layer is formed there and moving surfaces do not directly rub against each other. Interlocking of irregularities is avoided to a great extent. Movement becomes smooth. The substances which reduce friction are called lubricants. In some machines it may not be advisable to use oil as lubricant. There is an air cushion between the moving parts is used to reduce friction.