Dynamic friction as compared to static friction is
Same
More
Less
May be less of more depending on nature of surfaces and velocity
Correct Answer :
C. Less
Related Questions
The maximum velocity of a particle moving with simple harmonic motion is
ω
ωr
ω2r
ω/r
Which of the following is not a vector quantity?
Weight
Velocity
Acceleration
Force
When the lift is moving upwards with some acceleration, the pressure exerted by a man is __________ to its acceleration.
Directly proportional
Inversely proportional
Cube root
None of these
A single force and a couple acting in the same plane upon a rigid body
Balance each other
Cannot balance each other
Produce moment of a couple
Are equivalent
The acceleration of a particle moving with simple harmonic motion is __________ at the mean position.
Zero
Minimum
Maximum
None of these
Lami's theorem states that
Three forces acting at a point will be in equilibrium
Three forces acting at a point can be represented by a triangle, each side being proportional to force
If three forces acting upon a particle are represented in magnitude and direction by the sides of a triangle, taken in order, they will be in equilibrium
If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two
Which of the following do not have identical dimensions?
Momentum and impulse
Torque and energy
Torque and work
Moment of a force and angular momentum.
In a framed structure, as shown in the below figure, the forces in the members AB and BC are respectively 
√3. W (tensile) and 2W (compressive)
2W (tensile) and √3. W (compressive)
2√3. W (tensile) and 2√3. W (compressive)
None of the above
A body of weight W is required to move up on rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tanφ = Coefficient of friction between the plane and the body.)
P = W tanα
P = W tan (α + φ)
P = W (sinα + μcosα)
P = W (cosα + μsinα)
The linear velocity of a body rotating at ω rad/s along a circular path of radius r is given by
ω/r
ω.r
ω2/r
ω2.r
Forces are called coplanar when all of them acting on body lie in
One point
One plane
Different planes
Perpendicular planes
The power developed by a body acted upon by a torque T Newton metre (N - m) and revolving at ω radian/s is given by
T.ω (in watts)
T.ω/60 (in watts)
T.ω/75 (in kilowatts)
T.ω/4500 (in kilowatts)
In actual machines, mechanical advantage is __________ velocity ratio.
Equal to
Less than
Greater than
None of these
The mechanical advantage of a lifting machine is the ratio of
Distance moved by effort to the distance moved by load
Load lifted to the effort applied
Output to the input
All of the above
The range of projectile will be maximum for a given velocity of projectile, when the angle of projection (α) is
β/2
30° + β/2
45° + β/2
60° + β/2
If three forces acting in one plane upon a rigid body, keep it in equilibrium, then they must either
Meet in a point
Be all parallel
At least two of them must meet
All the above are correct
The maximum efficiency of a lifting machine is
1/m
V.R./m
m/V.R.
1/(m × V.R.)
Two forces are acting at an angle of 120°. The bigger force is 40 N and the resultant is perpendicular to the smaller one. The smaller force is
20 N
40 N
120 N
None of these
If the resultant of two equal forces has the same magnitude as either of the forces, then the angle between the two forces is
30°
60°
90°
120°
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 moment of inertia of a square of side a about its diagonal is
a2/8
a3/12
a4/12
a4/16
The time of flight of a projectile on downward inclined plane depends upon
Angle of projection
Angle of inclination of the plane
Both (A) and (B)
None of these
The law of the machine is (where P = Effort applied to lift the load, m = A constant which is equal to the slope of the line, W = Load lifted, and C = Another constant which represents the machine friction.)
P = mW - C
P = m/W + C
P = mW + C
P = C - mW
The force, by which the body is attracted, towards the centre of the earth, is called
Impulsive force
Mass
Weight
Momentum
The velocity ratio of a differential wheel and axle with D as the diameter of effort wheel and d1 and d2 as the diameters of larger and smaller axles respectively, is
D/(d₁ + d₂)
D/(d₁ - d₂)
2D/(d₁ + d₂)
2D/(d₁ - d₂)
A machine having an efficiency greater than 50%, is known as
Reversible machine
Non-reversible machine
Neither reversible nor non-reversible machine
Ideal machine
For a self locking machine, the efficiency must be
Equal to 50 %
Less than 50 %
Greater than 50 %
100 %
If the masses of both the bodies, as shown in the below figure, are doubled, then the acceleration in the string will be 
Same
Half
Double
None of these
Which of the following is not the unit of power?
kW (kilowatt)
hp (horse power)
kcal/sec
kcal/kg sec
A smooth cylinder lying on a __________ is in neutral equilibrium.
Curved surface
Convex surface
Horizontal surface
None of these