Question

The substance that helps to_______ friction is called lubricants.
(A) Increase
(B) Decrease
(C) Create
(D) Eliminate

Answer 1

Hint: Friction is a force that resists the relative motion between two objects or materials. The causes of this resistive force are molecular adhesion, surface roughness and deformations friction has both and disadvantages as well as many applications in our daily life.

Complete step-by-step solution: Friction is basically the force which opposes the motion of an object. Sometimes it favors the motion. It exists due to irregularities in the surfaces.
Friction is needed to be reduced since it causes wear and tear in machine parts, deformation of surfaces and energy is wasted as it is dissipated in the form of heat.
One way to reduce friction is to make the surfaces smoother. Making surfaces smoother decreases the unevenness of surfaces and reduces friction. We know the fraction appears because of the interaction between charged particles of the two bodies near the surface of contact. Hence, using surface smoother always helps. Smothering of surfaces can be done by polishing or using lubricants.
Lubricants are usually organic, slippery substances used for making the surfaces smooth and reduce friction.

Hence, option (A) is correct.

Note: There are many other ways of reducing friction. i.e. streamlining the bodies to reduce friction in fluids, known as drag. Drag basically makes the surface such that there is least contact between them. One another way to reduce friction is to make surfaces spherical in shape as a sphere has the least surface area.