The static friction

A bears a constant ratio to the normal reaction between the two surfaces
B is independent of the area of contact, between the two surfaces
C always acts in a direction, opposite to that in which the body tends to move
D all of the mentioned

Correct Answer: all of the mentioned

The laws of static friction are: a) The force of friction always acts in a direction, opposite to that in which the body tends to move. b) The magnitude of the force of friction is exactly equal to the force, which tends to move. c) The force of friction is independent of the area of contact, between the two surfaces. d) The force of friction depends upon the roughness of the surfaces.
Bissoy MCQ
#Machine Kinematics #Friction of Pivot and Collar Bearing

Related Questions

Dynamic friction as compared to static friction is
A Same
B More
C Less
D May be less of more depending on nature of surfaces and velocity
The ratio of static friction to dynamic friction is always
A Equal to one
B Less than one
C Greater than one
D None of these
Static friction is always __________ dynamic friction.
A Equal to
B Less than
C Greater than
D None of these
In which of the following circumstance should you use a static reference to a non static method?
A Making a method call using parent
B Making a method call using child
C Making an object call using parent
D Making an object call using child
The following is not a law of static friction:
A The force of friction always acts in a direction opposite to that in which the body tends to move
B The force of friction is dependent upon the area of contact
C The force of friction depends upon the roughness of the surface
D The magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces
The dynamic friction is the friction experienced by a body, when the body
A is in motion
B is at rest
C just begins to slide over the surface of the other body
D none of the mentioned
Coulomb friction is the friction between
A Bodies having relative motion
B Two dry surfaces
C Two lubricated surfaces
D Solids and liquids
A friction circle is a circle drawn when a journal rotates in a bearing. Its radius depends upon the coefficient of friction and the
A Magnitude of the forces on journal
B Angular velocity of journal
C Clearance between journal and bearing
D Radius of journal
For a shoe brake, the equivalent coefficient of friction is equal to (where $$\mu $$ = Actual coefficient of friction and $$\theta $$ = Semi-block angle)
A $$\frac{{2\mu \sin \theta }}{{\theta + \sin \theta }}$$
B $$\frac{{\mu \sin \theta }}{{2\theta + \sin 2\theta }}$$
C $$\frac{{4\mu \sin \theta }}{{\theta + \sin \theta }}$$
D $$\frac{{4\mu \sin \theta }}{{2\theta + \sin 2\theta }}$$
The radius of a friction circle for a shaft rotating inside a bearing is (where r = Radius of shaft and $$\tan \varphi $$  = Coefficient of friction between the shaft and bearing)
A $${\text{r}}\sin \varphi $$
B $${\text{r}}\cos \varphi $$
C $${\text{r}}\tan \varphi $$
D $$\frac{{\text{r}}}{2}\cos \varphi $$

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