Hart mechanism has
Eight links
Six links
Four links
Twelve links
Correct Answer :
B. Six links
Related Questions
In a disc clutch, if there are n₁ number of discs on the driving shaft and n₂ number of discs on the driven shaft, then the number of pairs of contact surfaces will be
n₁ + n₂
n₁ + n₂ + 1
n₁ + n₂ - 1
n₁ + n₂ - 2
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)
The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where l₁ and l₂ = Distance of two masses from the centre of gravity of the body, and kG = Radius of gyration of the body)
l₁ = kG
l₂ = kG
l₁l₂ = kG
l₁l₂ = kG²
The locus of a point on a thread unwound from a cylinder will be
A straight line
A circle
Involute
Cycloidal
What is the number of instantaneous centres for an eight link mechanism?
15
28
30
8
When a ship travels in a sea, which of the effect is more dangerous
Steering
Pitching
Rolling
All of the above
Which of the following is false statement in respect of differences between machine and structure?
Machines transmit mechanical work, whereas structures transmit forces
In machines, relative motion exists between its members, whereas same does not exist in case of structures
Machines modify movement and work, whereas structures modify forces
Efficiency of machines as well as structures is below 100%
The coefficient of fluctuation of speed is __________ of maximum fluctuation of speed and the mean speed.
Sum
Difference
Product
Ratio
The frequency of oscillation at compared to earth will be
6 times more
6 times less
2.44 times more
2.44 times less
The number of centers in a crank driven slider crank mechanism is
0
2
4
6
The velocity of any point in mechanism relative to any other point on the mechanism on velocity polygon is represented by the line
Joining the corresponding points
Perpendicular to line as per (A)
Not possible to determine with these data
At 45° to line as per (A)
Pitch point on a cam is
Any point on pitch curve
The point on cam pitch curve having the maximum pressure angle
Any point on pitch circle
The point on cam pitch curve having the minimum pressure angle
Creep in belt drive is due to
Material of the pulley
Material of the belt
Larger size of the driver pulley
Uneven extensions and contractions due to varying tension
The periodic time is given by (where ω = Angular velocity of the particle in rad/s)
ω/2π
2π/ω
ω × 2π
π/ω
A thin circular disc is rolling with a uniform linear speed, along a straight path on a plane surface. Which of the following statement is correct in this regard?
All points of the disc have the same velocity
The centre of the disc has zero acceleration
The centre of the disc has centrifugal acceleration
The point on the disc making contact with the plane surface has zero acceleration
When two links are connected by a pin joint, their instantaneous centre lies
On their point of contact
At the centre of curvature
At the centre of circle
At the pin joint
Which of the following is a spring controlled governor?
Hartnell governor
Hartung governor
Wilson-Hartnell governor
All of these
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
A governor is said to be stable, if the
Radius of rotation of balls increases as the equilibrium speed decreases
Radius of rotation of balls decreases as the equilibrium speed decreases
Radius of rotation of balls increases as the equilibrium speed increases
Radius of rotation of balls decreases as the equilibrium speed increases
A universal joint is an example of
Higher pair
Lower pair
Rolling pair
Sliding pair
Ball and a Socket forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
The critical speed of a shaft depends upon its
Mass
Stiffness
Mass and stiffness
Stiffness and eccentricity
The velocity of a particle moving with simple harmonic motion, at any instant is given by (where ω = Displacement of the particle from mean position)
ω √(x² - r²)
ω √(r² - x²)
ω² √(x² - r²)
ω² √(r² - x²)
A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The total acceleration of B with respect to A will be equal to
Vector sum of radial component and coriolis component
Vector sum of tangential component and coriolis component
Vector sum of radial component and tangential component
Vector difference of radial component and tangential component
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
Efficiency of a screw jack is given by
tan (α + φ)/tanα
tanα/tan (α +φ)
tan (α - φ)/tanα
tanα/tan (α - φ)
In S.H.M., acceleration is proportional to
Velocity
Displacement
Rate of change of velocity
All of the above
In a hydrodynamic journal bearing, there is
A very thin film of lubricant between the journal and the bearing such that there is contact between the journal and the bearing
A thick film of lubricant between the journal and the bearing
No lubricant between the journal and the bearing
A forced lubricant between the journal and the bearing
The amplitude of vibration is always __________ the radius of the circle.
Equal to
Less than
Greater than
None of these
The example of rolling pair is
Bolt and nut
Lead screw of a lathe
Ball and socket joint
Ball bearing and roller bearing