Friction Test -...

Friction on a dry marble floor is ----- than that on a wet marble floor.

Friction reduces efficiency of machines due to:

Unevenness in the surfaces of the moving body and the surface on which it moves causes:

Any substance which is used to reduce the roughness of a surface is called a:

Friction can be increased by increasing:

Boats and aeroplanes are ................. so as to reduce fluid friction.fill in the blank.

Frictional force increases when surfaces in contact are made very smooth, because of 

Friction between any two objects is due to

Graphite powder is used in machines to

To keep machines running smoothly and to avoid wear and tear of machines, the best and the most commonly used lubricant is: