Question

If we imagine 2 ideally smooth surfaces kept in contact, the frictional force acting between them is equal to:
(A) Zero
(B) A finite value but not zero
(C) Very large
(D) We can't predict

Answer 1

Hint
An ideally smooth surface is a surface that has a coefficient of friction of 0. This means that a body which had some initial velocity will retain its velocity when traversing through this surface. ideally this case is not possible and everybody faces resistance when it is moving. This resistance can be in the form of frictional force or vicious force

Complete step by step answer
We also know that the frictional force between 2 bodies is directly proportional to the normal reaction of that surface on that body. But after removing the proportionality sign, we get a constant. This constant is known as the coefficient of friction. It is denoted by $\mu$ . If its value is 0, i.e. when the surface is completely smooth, the force of friction acting on it will be 0.
Therefore the correct answer is option (A).

Note
Actually, there are 2 kinds of the coefficient of friction. One of them is known as the coefficient of static friction and the other is known as the coefficient of kinetic friction. Static comes into play when the body is stationary and is subjected to some load. The kinetic friction comes into play when the body is in motion and some force is acting on it.