Question

132
Out of the following, the lubricant to be used in the moving parts of a machine is
(b) air
(c) chalk powder (d) turpentine oil
(a) water
Smooth surface has
(a) less frictional force
(b) more frictional force
(c) Sometimes less and sometimes more force. (d) all the above
Ans
To convert the static or sliding friction into rolling friction, the heavy luggage carriers are attached
(5)
at their base.
with
(b) chains
(c) tyres
(d) wheels
(a) ball bearings
Oo​

Answer 1

smooth surface has less frictional force....

I think that is right can you thank me for me please.....