reaction of any smooth surface with which the body is in contact

reaction of a rough surface of a body which rolls on it without slipping

reaction at a point or an axis, fixed in space, around which a body is con-strained to turn

all of these

maximum

minimum

zero

infinity

20 kg, - ve sense

10 kg, - ve sense

20 kg, + ve sense

10 kg, + ve sense

angle between normal reaction and the resultant of normal reaction and the limiting friction

ratio of limiting friction and normal reaction

the ratio of minimum friction force to the friction force acting when the body is just about to move

the ratio of minimum friction force to friction force acting when the body is in motion

area of contact

shape of surfaces

strength of surfaces

nature of surface