In vibration isolation system, if ω/ωn > 1, then the phase difference between the transmitted force and the disturbing force is
0°
90°
180°
270°
Correct Answer :
C. 180°
Related Questions
Which of the following is a spring controlled governor?
Hartnell governor
Hartung governor
Wilson-Hartnell governor
All of these
Klein's construction gives a graphic construction for
Slider-crank mechanism
Velocity polygon
Acceleration polygon
Four bar chain mechanism
The maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)
sin (θ + φ) + 1/ cos (θ - φ) + 1
cos (θ - φ) + 1/ sin (θ + φ) + 1
cos (θ + φ) + 1/ cos (θ - φ) + 1
cos (θ - φ) + 1/ cos (θ + φ) + 1
Torsional vibrations are said to occur when the particles of a body moves
Perpendicular to its axis
Parallel to its axis
In a circle about its axis
None of these
A kinematic chain requires at least
2 links and 3 turning pairs
3 links and 4 turning pairs
4 links and 4 turning pairs
5 links and 4 turning pairs
In a cam drive with uniform velocity follower, the sharp corners of the displacement diagram are rounded off at the beginning and at the end of each stroke. This is done
Because of difficulty in manufacturing cam profile
Because of loose contact of follower with cam surface
In order to have acceleration in beginning and retardation at the end of stroke within the finite limits
Because the uniform velocity motion is a partial parabolic motion
The number of links and instantaneous centers in a reciprocating engine mechanism are
4, 4
4, 5
5, 4
4, 6
A Hartnell governor is a
Dead weight governor
Pendulum type governor
Spring loaded governor
Inertia governor
Frequency of vibrations is usually expressed in
Number of cycles per hour
Number of cycles per minute
Number of cycles per second
None of these
The periodic time of one oscillation for a simple pendulum is
2π. √(g/l)
(1/2π). √(g/l)
2π. √(l/g)
(1/2π). √(l/g)
The critical speed of a shaft depends upon its
Mass
Stiffness
Mass and stiffness
Stiffness and eccentricity
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
A chain comprises of 5 links having 5 joints. Is it kinematic chain?
Yes
No
It is a marginal case
Data are insufficient to determine it
A mechanism __________ for transmitting or transforming motion.
Can be used
Cannot be used
Unpredictable
None of these
Power of a governor is the
Mean force exerted at the sleeve for a given percentage change of speed
Workdone at the sleeve for maximum equilibrium speed
Mean force exerted at the sleeve for maximum equilibrium speed
None 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, the acceleration of the piston is _________ when the crank OC and connecting rod PC are at right angles to each other. 
Infinity
Zero
Any +ve value
Any -ve value
The example of spherical pair is
Bolt and nut
Lead screw of a lathe
Ball and socket joint
Ball bearing and roller bearing
The frictional torque transmitted in a conical pivot bearing with assumption of uniform pressure is __________ as compared to uniform wear.
Less
More
Same
None of these
The frictional torque transmitted in a truncated conical pivot bearing, considering uniform wear, is
(1/2). μ W cosec α (r₁ + r₂)
(2/3).μ W cosec α (r₁ + r₂)
(1/2). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
Balancing of rotating and reciprocating parts of an engine is necessary when it runs at
Slow speed
Moderate speed
Highs peed
Any one of these
Angle of ascent of cam is defined as the angle
During which the follower returns to its initial position
Of rotation of the cam for a definite displacement of the follower
Through which the cam rotates during the period in which the follower remains in highest position
Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
The equation of motion for a vibrating system with viscous damping is (d²x/dt²) + (c/m). (dx/dt) + (s/m). x = 0 If the roots of this equation are real, then the system will be
Over-damped
Under damped
Critically damped
Without vibrations
When the pitching of a ship is __________ the effect of gyroscopic couple acting on it will be to move the ship towards port side.
Upward
Downward
Forward
Backward
A slider crank chain consists of following numbers of turning and sliding pairs
1, 3
2, 2
3, 1
4, 0
Longitudinal vibrations are said to occur when the particles of a body moves
Perpendicular to its axis
Parallel to its axis
In a circle about its axis
None of these
The acceleration of a particle at any instant has two components i.e. radial component and tangential component. These two components will be
Parallel to each other
Perpendicular to each other
Inclined at 45°
Opposite to each other
When the pitching of a ship is upward, the effect of gyroscopic couple acting on it will be
To move the ship towards starboard
To move the ship towards port side
To raise the bow and lower the stern
To raise the stern and lower the bow
The magnitude of linear velocity of a point B on a link AB relative to point A is (Where ω = Angular velocity of the link AB)
ω × AB
ω × (AB)²
ω² × AB
(ω × AB)²
A rotary internal combustion engine has __________ cylinders.
Four
Five
Six
Seven
The length of a simple pendulum which gives the same frequency as the compound pendulum, is
kG + l₁
kG² + l₁
(kG² + l₁²)/ l₁
(kG + l₁²)/ l₁