In vibration isolation system, the transmissibility will be equal to unity, for all values of damping factor, if ω/ωn is
Equal to 1
Equal to 2
Less than 2
Greater than 2
Correct Answer :
B. Equal to 2
Related Questions
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 balancing of a rigid rotor can be achieved by appropriately placing balancing masses in
A single plane
Two planes
Three planes
Four planes
The product of the diametral pitch and circular pitch is equal to
1
1/π
π
2 π
An exact straight line motion mechanism is a
Scott-Russell's mechanism
Hart's mechanism
Peaucellier's mechanism
All of these
The velocity of the rubbing surface __________ with the distance from the axis of the bearing.
Increases
Decreases
Remain same
None of these
The indicator using Watt mechanism is known as
Thompson indicator
Richard indicator
Simplex indicator
Thomson indicator
Length of arc of contact is given by
Arc of approach - Arc of recess
Arc of approach + Arc of recess
Arc of approach / Arc of recess
Arc of approach × Arc of recess
The instantaneous centres which vary with the configuration of mechanism are called
Permanent instantaneous centres
Fixed instantaneous centres
Neither fixed nor permanent instantaneous centres
None of the above
Klein's construction gives a graphic construction for
Slider-crank mechanism
Velocity polygon
Acceleration polygon
Four bar chain mechanism
The example of completely constrained motion is a
Motion of a piston in the cylinder of a steam engine
Motion of a square bar in a square hole
Motion of a shaft with collars at each end in a circular hole
All of the above
Which of the following statement is correct?
For constant velocity ratio transmission between two gears, the common normal at the point of contact must always pass through a fixed point on the line joining the centres of rotation of gears.
For involute gears, the pressure angle changes with the change in centre distance between gears.
The epicyclic gear trains involve rotation of atleast one gear axis about some other gear axis.
All of the above
The relation between number of pairs (p) forming a kinematic chain and the number of links (l) is
l = 2p - 2
l = 2p - 3
l = 2p - 4
l = 2p - 5
In a reciprocating steam engine, which of the following forms a kinematic link?
Cylinder and piston
Piston rod and connecting rod
Crankshaft and flywheel
Flywheel and engine frame
The power transmitted by a belt is maximum when the maximum tension in the belt is _________ of centrifugal tension.
One-third
Two-third
Double
Three times
The acceleration of a particle moving with simple harmonic motion, at any instant is given by
ωx
ω²x
ω²/x
ω³/x
When the elements of a pair are kept in contact by the action of external forces, the pair is said to be a
Lower pair
Higher pair
Self-closed pair
Force-closed pair
The frictional torque transmitted in a flat pivot bearing, assuming uniform wear, is (Where μ = Coefficient of friction, W=Load over the bearing, R=Radius of bearing)
μwr
¾μWR
(2/3) μWR
½μWR
The swaying couple is due to the
Primary unbalanced force
Secondary unbalanced force
Two cylinders of locomotive
Partial balancing
Which of the following mechanism is obtained from lower pair?
Gyroscope
Pantograph
Valve and valve gears
All of the above
The arrangement is called bevel gearing, when two __________ are connected by gears.
Intersecting and coplanar shafts
Nonintersecting and non-coplanar shafts
Parallel and coplanar shafts
Parallel and non-coplanar shafts
In a drag link quick return mechanism, the shortest link is always fixed. The sum of the shortest and longest link is
Equal to sum of other two
Greater than sum of other two
Less than sum of other two
There is no such relationship
Which of the following statement is wrong?
A round bar in a round hole form a turning pair
A square bar in a square hole form a sliding pair
A vertical shaft in a foot step bearing forms a successful constraint
All of the above
Under logarithmic decrement, the amplitude of successive vibrations are
Constant
In arithmetic progression
In geometric progression
In logarithmic progression
Which of the following is an inversion of a single slider crank chain?
Pendulum pump
Oscillating cylinder engine
Rotary internal combustion engine
All of these
In under damped vibrating system, if x₁ and x₂ are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to
x₁/x₂
log(x₁/x₂)
loge(x₁/x₂)
log(x₁.x₂)
The Grubler's criterion for determining the degrees of freedom (n) of a mechanism having plane motion is (where l = Number of links, and j = Number of binary joints)
n = (l -1) - j
n = 2(l - 1) - 2j
n = 3(l - 1) - 2j
n = 4(l - 1) - 3j
The swaying couple is maximum or minimum when the angle of inclination of the crank to the line of stroke (θ) is equal to
90° and 180°
45° and 225°
180° and 270°
270° and 360°
In a simple train of wheels, the velocity ratio __________ the intermediate wheels.
Depends upon
Is independent of
Either A or B
None of these
A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The radial component of the acceleration of B with respect to A, is (where vBA = Linear velocity of B with respect to A)
vBA × AB
vBA /AB
v²BA
v²BA /AB
Sense of tangential acceleration of a link
Is same as that of velocity
Is opposite to that of velocity
Could be either same or opposite to velocity
Is perpendicular to that of velocity