Question

Match the following

List – I	List – II
a. Static friction	e. constant for a given pair of surfaces
b. Limiting friction	f. independent of area of contact
c. Kinetic friction	g. self adjusting
d. Rolling friction	h. has the least magnitude for a given normal reaction

• A. $a\to e;b\to f;c\to g;d\to h$
• B. $a\to h;b\to f;c\to e;d\to g$
• C. $a\to g;b\to e;c\to f;d\to h$
• D. $a\to g;b\to h;c\to f;d\to e$

Answer 1

The correct option is C $a\to g;b\to e;c\to f;d\to h$

Static friction will increase upto a certain limit by following the applied force. So it is self adjusting.

Limiting friction accounts for a threshold force required to cause motion. This depends on a interacting pair of surfaces.

Frictional force is proportional to the normal force. And the area A over which the normal force is distributed is given by pressure. That is force per unit area. So kinetic frictional force is independent of area of contact.

Since the objects are not perfectly rigid in real life. So when they roll on a surface then they deform and that deformation causes resistance. For a rolling motion surface of contact is very less so net normal force is also small and hence the rolling friction.