1. Home
  2. / Forum

User Forum

Ask Your Question
Radhika Gupta from Dps civil lines aligarh , Aligarh
Subject :NSO    Class : Class 6

Which of the following reduce friction?
(i)    Lubricants
(ii)   Ball bearings
(iii)  Smooth surface
(iv)   Rough surface

A(i) and (iii) only
B(ii) and (iii) only
C(ii) and (iv) only
D(i) , (ii) and (iii) only


Post Your Answer