Science- Friction

roughness of surface ✘ smoothness of surface ✘ inclination of surface ✘ all of these ✔

reduce friction ✘ increase friction ✘ both (a) and (b) ✘ none of these ✔

increase ✘ decrease ✘ disappear altogether ✘ will remain unchanged ✔

muddy surface ✘ polished marble surface ✘ cemented surface ✘ brick surface ✔

Surface of wet soap ✘ Surface of tyres ✘ Glazed tiles ✘ Surface of mirror ✔

Foe ✘ friend ✘ Both of these ✘ none of these ✔

force ✘ pressure ✘ friction ✘ drag ✔

dog ✘ bird ✘ car ✘ all of these ✔

Stone ✘ Plastic block ✘ Wooden block ✘ Glass block ✔

only if the objects are solid. ✘ only if one of the two objects is liquid. ✘ only if one of the two objects is gaseous. ✘ irrespective of whether the objects are solid, liquid or gaseous. ✔