Question

16. Give reasons :
A few drops of oil are poured on the hinges of a door.
(ii) Compressed and purified air is considered a good lubricant.
(ii) We use ball bearings in shafts of motors.​

Answer 1

Answer:

Few drops of oil are poured on the hinges of a door, the door moves smoothly by reducing friction. Oil is a lubricant. it helps to reduce friction by being applied over the irregularities of a surface. So, there is no interlocking of irregularities, so, friction reduces, and the door moves smoothly.