The lower pair is a
Open pair
Closed pair
Sliding pair
Point contact pair
Correct Answer :
B. Closed pair
Related Questions
A pulley and belt in a belt drive form a
Cylindrical pair
Turning pair
Rolling pair
Sliding pair
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)]
Klein's construction gives a graphic construction for
Slider-crank mechanism
Velocity polygon
Acceleration polygon
Four bar chain mechanism
The relative velocity of B with respect to A in a rigid link AB is
Parallel to AB
Perpendicular to AB
Along AB
At 45° to AB
Cam size depends upon
Base circle
Pitch circle
Prime circle
Outer circle
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
Which of the following statements regarding laws governing the friction between dry surfaces are correct?
The friction force is dependent on the materials of the contact surfaces.
The friction force is directly proportional to the normal force.
The friction force is independent of me area of contact.
All of the above
Which of the following statement is correct for involute gears?
The interference is inherently absent.
The variation in centre distance of shafts increases radial force.
A convex flank is always in contact with concave flank.
The pressure angle is constant throughout the teeth engagement.
For fluctuating loads, well suited bearing is
Ball bearing
Roller bearing
Needle roller bearing
Thrust bearing
Cross head and guides form a
Lower pair
Higher pair
Turning pair
Sliding pair
A spring controlled governor is said to be unstable 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
Remains constant for all radii of rotation
The Kutzbach criterion for determining the number of degrees of freedom (n) is (where l = number of links, j = number of joints and h = number of higher pairs)
n = 3(l - 1) - 2j - h
n = 2(l - 1) -2j - h
n = 3(l - 1) - 3j - h
n = 2(l - 1) - 3j - h
In a ball bearing, ball and bearing forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
Whitworth quick return mechanism is obtained by inversion of
Slider crank mechanism
Kinematic chain
Five link mechanism
Roller cam mechanism
When the crank is at the outer dead centre, in a reciprocating steam engine, then the acceleration of the piston will be
ω² r {(n + 1)/n}
ω² r {(n - 1)/n}
ω² r {n/(n + 1)}
ω² r {n/(n - 1)}
The motion between a pair which takes place in __________ is known as incompletely constrained motion.
One direction only
Two directions only
More than one direction
None of these
The lower pairs are __________ pairs.
Self-closed
Force-closed
Friction closed
None of these
In S.H.M., acceleration is proportional to
Velocity
Displacement
Rate of change of velocity
All of the above
The sense of coriolis component 2 ωv is same as that of the relative velocity vector v rotated at
45° in the direction of rotation of the link containing the path
45° in the direction opposite to the rotation of the link containing the path
90° in the direction of rotation of the link containing the path
180° in the direction opposite to the rotation of the link containing the path
The locus of a point on a thread unwound from a cylinder will be
A straight line
A circle
Involute
Cycloidal
The frequency of oscillation of a compound pendulum is
2π. √[gh/(kG² + h²)]
2π. √[(kG² + h²)/gh]
(1/2π). √[gh/(kG² + h²)]
(1/2π). √[(kG² + h²)/gh]
In a multiple V-belt drive, when a single belt is damaged, it is preferable to change the complete set to
Reduce vibration
Reduce slip
Ensure uniform loading
Ensure proper alignment
Which is the false statement about the properties of instantaneous centre?
At the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered
The two rigid links have no linear velocities relative to each other at the instantaneous centre
The two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link
The double centre can be denoted either by O2 or O12, but proper selection should be made
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)
Pitch point of a cam is
A point on the pitch curve having minimum pressure angle
A point on the pitch curve having maximum pressure angle
Any point on the pitch curve
Any point on the pitch circle
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
The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity ω₁ rad/s in the clockwise direction and the link OB turns with angular velocity ω₂ rad/s in the anticlockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)
ω₁.ω₂.r
(ω₁ - ω₂) r
(ω₁ + ω₂) r
(ω₁ - ω₂) 2r
A flywheel is fitted to the crankshaft of an engine having W as the amount of indicated work per revolution and permissible limits of coefficient of fluctuation of energy and speed as CE and CS respectively. The kinetic energy of the flywheel is given by
2 W CE / CS
W CE / 2CS
W CE / CS
W CS / 2CE
The frictional torque transmitted in a flat collar bearing, considering uniform wear, 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)]
The critical speed of a shaft in revolution per second is __________ as that of natural frequency of transverse vibration.
Same
Different
Unpredictable
None of these