Angle of friction is the
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
Correct Answer :
A. Angle between normal reaction and the resultant of normal reaction and the limiting friction
Related Questions
The total motion possessed by a body, is called
Impulsive force
Mass
Weight
Momentum
A framed structure, as shown in the below figure, is a 
Perfect frame
Deficient frame
Redundant frame
None of the above
According to parallel axis theorem, the moment of inertia of a section about an axis parallel to the axis through centre of gravity (i.e. IP) is given by(where, A = Area of the section, IG = Moment of inertia of the section about an axis passing through its C.G., and h = Distance between C.G. and the parallel axis.)
IP = IG + Ah2
IP = IG - Ah2
IP = IG / Ah2
IP = Ah2 / IG
The periodic time (T) is given by (where, ω = Angular velocity of particle in rad/s.)
ω/2π
2π/ω
2π × ω
π/ω
Moment of inertia of a rectangular section having width (b) and depth (d) about an axis passing through its C.G. and parallel to the width (b), is
db³/12
bd³/12
db³/36
bd³/36
The periodic time of one oscillation for a simple pendulum is (where l = Length of the pendulum.)
(1/2π). √(l/g)
(1/2π). √(g/l)
2π. √(l/g)
None of these
Two blocks A and B of masses 150 kg and 50 kg respectively are connected by means of a string as shown in the below figure. The tension in all the three strings __________ be same. 
Will
Will not
Either A or B
None of these
The forces which meet at one point, but their lines of action __________ on the same plane, are Known as non-coplanar concurrent forces.
Lie
Do not lie
Either A or B
None of these
A force is completely defined when we specify
Magnitude
Direction
Point of application
All of the above
Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its vertex and parallel to the base, is __________ than that passing through its C.G. and parallel to the base.
Nine times
Six times
Four times
Two times
A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve
Circular arc
Parabola
Hyperbola
Elliptical
The C.G. of a solid hemisphere lies on the central radius 3r
At distance from the plane base 3r
At distance from the plane base 3r
At distance from the plane base 3r
At distance from the plane base
Mass moment of inertia of a uniform thin rod of mass M and length (l) about its mid-point and perpendicular to its length is
(2/3) Ml2
(1/3) Ml2
(3/4) Ml2
(1/12) Ml2
The amplitude is always __________ radius of the circle.
Equal to
Less than
Greater than
None of these
Moment of inertia of a circular section about an axis perpendicular to the section is
πd3/16
πd3/32
πd4/32
πd4/64
The moment of inertia of a rectangular section 3 cm wide and 4 cm deep about X-X axis is
9 cm4
12 cm4
16 cm4
20 cm4
The unit of work in S.I. units is
Newton
erg
kg-m
joule
The moment of a force
Is the turning effect produced by a force, on the body, on which it acts
Is equal to the product of force acting on the body and the perpendicular distance of a point and the line of action of the force
Is equal to twice the area of the triangle, whose base is the line representing the force and whose vertex is the point, about which the moment is taken
All of the above
A framed structure is imperfect, if the numbers of members are __________ (2j - 3).
Equal to
Less than
Greater than
Either (B) or (C)
Two non-collinear parallel equal forces acting in opposite direction
Balance each other
Constitute a moment
Constitute a couple
Constitute a moment of couple
For a self locking machine, the efficiency must be
Equal to 50 %
Less than 50 %
Greater than 50 %
100 %
Three forces acting on a rigid body are represented in magnitude, direction and line of action by the three sides of a triangle taken in order. The forces are equivalent to a couple whose moment is equal to
Area of the triangle
Twice the area of the triangle
Half the area of the triangle
None of these
Which of the following statement is correct?
The algebraic sum of the forces, constituting the couple is zero
The algebraic sum of the forces, constituting the couple, about any point is the same
A couple cannot be balanced by a single force but can be balanced only by a couple of opposite sense
All of the above
One watt is equal to
0.1 joule/s
1 joule/s
10 joules/s
100 joules/s
Coplanar non-concurrent forces are those forces which __________ at one point, but their lines of action lie on the same plane.
Meet
Do not meet
Either A or B
None of these
The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is known as
Principle of independence of forces
Principle of resolution of forces
Principle of transmissibility of forces
None of these
When a rigid body is suspended vertically, and it oscillates with a small amplitude under the action of the force of gravity, the body is known as
Simple pendulum
Compound pendulum
Torsional pendulum
Second's pendulum
The static friction
Bears a constant ratio to the normal reaction between the two surfaces
Is independent of the area of contact, between the two surfaces
Always acts in a direction, opposite to that in which the body tends to move
All of the above
The rate of change of displacement of a body is called
Velocity
Acceleration
Momentum
None of these
Moment of inertia of a hollow circular section, as shown in the below figure about X-axis, is 
π/16 (D² - d²)
π/16 (D³ - d³)
π/32 (D⁴ - d⁴)
π/64 (D⁴ - d⁴)