The danger of breakage and vibration is maximum
Below the critical speed
Near the critical speed
Above the critical speed
None of these
Correct Answer :
B. Near the critical speed
Related Questions
The ratio of the number of teeth to the pitch circle diameter in millimetres, is called
Circular pitch
Diametral pitch
Module
None of these
If two moving elements have surface contact in motion, such pair is known as
Sliding pair
Rolling pair
Surface pair
Higher pair
Shaft revolving in a bearing is the following type of pair
Lower pair
Higher pair
Spherical pair
Cylindrical pair
When a ship travels in a sea, which of the effect is more dangerous
Steering
Pitching
Rolling
All of the above
In higher pair, the relative motion is
Purely turning
Purely sliding
Purely rotary
Combination of sliding and turning
Angle of dwell of cam is defined as the angle
During which the follower returns to its initial position
Of rotation of the cam for definite displacement of the follower
Through which the cam rotates during the period in which the follower remains in the highest position
Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
Tangential acceleration direction is
Along the angular velocity
Opposite to angular velocity
May be any one of these
Perpendicular to angular velocity
When the axes of the first and last wheels are coaxial, then the train is known as
Simple train of wheels
Compound train of wheels
Reverted gear train
Epicyclic gear train
A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if
The sum of the two masses is equal to the total mass of body
The centre of gravity of the two masses coincides with that of the body
The sum of mass moment of inertia of the masses about their centre of gravity is equal to the mass moment of inertia of the body
All of the above
In the below figure, PC is the connecting rod and OC is the crank making an angle θ with the line of stroke PO and rotates with uniform angular velocity at ω rad/s. The Klien's acceleration diagram for determining the acceleration of the piston P is shown by quadrilateral CQNO, if N coincides with O, then 
Acceleration and velocity of the piston P is zero
Acceleration and velocity of the piston P is maximum
Acceleration of the piston P is zero and its velocity is maximum
Acceleration of the piston P is maximum and its velocity is zero
The frictional torque transmitted in a flat collar bearing, considering uniform pressure, is (where r₁ and r₂ = External and internal radii of collar respectively)
(1/2). μ W (r₁ + r₂)
(2/3). μ W (r₁ + r₂)
(1/2). μ W [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3). μ W [(r₁³ - r₂³)/(r₁² - r₂²)]
A pantograph is a mechanism with
Lower pairs
Higher pairs
Rolling pairs
Turning pairs
For the brake to be self locking, the force P at C shown in the below figure, should 
Be zero
Act in upward direction
Act in downward direction
None of these
The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
Structure
Machine
Inversion
Compound mechanism
In a screw jack, the effort required to lower the load W is given by
P = W tan(α - φ)
P = W tan(α + φ)
P = W tan(φ - α)
P = W cos(α + φ)
TJIE horse power transmitted by a belt is dependent upon
Tension on tight side of belt
Tension on slack side of belt
Radius of pulley
All of the above
The displacement of a flat faced follower when it has contact with the flank of a circular arc cam, is given by (where R = Radius of flank, r₁ = Minimum radius of the cam, and θ = Angle turned through by the cam)
R (1 - cosθ)
(R - r₁) (1 - cosθ)
R (1 - sinθ)
(R - r₁) (1 - sinθ)
Klein's construction is useful to determine
Velocity of various parts
Acceleration of various parts
Displacement of various parts
Angular acceleration of various parts
A spring controlled governor is said to be isochronous when the controlling force
Increases as the radius of rotation decreases
Increases as the radius of rotation increases
Decreases as the radius of rotation increases
Remain constant for all radii of rotation
The pressure angle of a cam is the angle between the direction of the follower motion and a normal to the
Pitch circle
Base circle
Pitch curve
Prime circle
The pair is known as a higher pair, when the relative motion between the elements of a pair is
Turning only
Sliding only
Rolling only
Partly turning and partly sliding
The contact ratio for gears is
Zero
Less than one
Greater than one
Infinity
Lower pairs are those which have
Point or line contact between the two elements when in motion
Surface contact between the two elements when in motion
Elements of pairs not held together mechanically
Two elements that permit relative motion
The centre of percussion is below the centre of gravity of the body and is at a distance equal to
h/kG
h²/kG
kG²/h
h × kG
According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centers lie on
A triangle
A point
Two lines
A straight line
The natural frequency of free longitudinal vibrations is equal to (where m = Mass of the body, s = Stiffness of the body, and δ = Static deflection of the body)
1/2π × √(s/m)
1/2π × √(g/δ)
0.4985/√δ
Any one of these
The natural frequency of free transverse vibrations due to a point load acting over a simply supported shaft is equal to (where δ = Static deflection of a simply supported shaft due to the point load)
0.4985/√δ
0.5615/√δ
0.571/√δ
0.6253/√δ
A simple spring-mass vibrating system has a natural frequency of fn. If the spring stiffness is halved and the mass is doubled, then the natural frequency will become
fn/2
2 fn
4 fn
8 fn
A mechanism consisting of four links is called a __________ mechanism.
Simple
Compound
Binary
None of these
The maximum value of the pressure angle in case of cam is kept as
10°
14°
20°
30°