A kinematic chain is known as a mechanism when
None of the links is fixed
One of the links is fixed
Two of the links are fixed
None of these
Correct Answer :
B. One of the links is fixed
Related Questions
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
When the relation between the controlling force (Fc) and radius of rotation (r) for a spring controlled governor is Fc = ar + b, then the governor will be
Stable
Unstable
Isochronous
None of these
For the same lift and same angle of ascent, a smaller base circle will give
A small value of pressure angle
A large value of pressure angle
There is no such relation with pressure angle
Something else
The mechanism forms a structure, when the number of degrees of freedom (n) is equal to
0
1
2
-1
When the nature of contact between the elements of a pair is such that it can only slide relative to the other, the pair is known as a
Screw pair
Spherical pair
Turning pair
Sliding pair
The direction of linear velocity of any point on a link with respect to another point on the same link is
Parallel to the link joining the points
Perpendicular to the link joining the points
At 45° to the link joining the points
None of the above
The secondary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, θ = Angle of inclination of crank with the line of stroke, and n = Ratio of the length of connecting rod to radius of crank)
m.ω².r sinθ
m.ω².r cosθ
m.ω².r (sin 2θ/n)
m.ω².r (cos 2θ/n)
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
Higher 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 transmissibility, for all values of damping factor, will be less than unity, if ω/ωn is
Equal to 1
Less than 2
Equal to 2
Greater than 2
In a circular arc cam with roller follower, the acceleration in any position of the lift will depend only upon
Total lift, total angle of lift, minimum radius of cam and cam speed
Radius of circular arc, cam speed, location of centre of circular arc and roller diameter
Mass of cam follower linkage, spring stiffness and cam speed
Total lift, centre of gravity of the cam and cam speed
Transmission of power from the engine to the rear axle of an automobile is by means of
Compound gears
Worm and wheel method
Hooke's joint
Crown gear
A foot step bearing and rotor of a vertical turbine form examples of
Incompletely constrained motion
Partially constrained motion
Completely constrained motion
Successfully constrained motion
The acceleration of a particle moving with simple harmonic motion, at any instant is given by
ωx
ω²x
ω²/x
ω³/x
The lower pairs are __________ pairs.
Self-closed
Force-closed
Friction closed
None of these
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
For high speed engines, the cam follower should move with
Uniform velocity
Simple harmonic motion
Uniform acceleration and retardation
Cycloidal motion
Which of the following property of the instantaneous centre is correct?
A rigid link rotates instantaneously relative to another link at the instantaneous centre for the configuration of the mechanism considered.
The two rigid links have no linear velocity relative to each other at the instantaneous centre.
The velocity of the instantaneous centre relative to any third rigid link is same whether the instantaneous centre is regarded as a point on the first rigid link or on the second rigid link.
All of the above
If ω/ωn is very low for a body vibrating under steady state vibrations, the phase angle for all values of damping factors, will tend to approach
0°
90°
180°
360°
In a Hartnell governor, if a spring of greater stiffness is used, then the governor will be
Less sensitive
More sensitive
Unaffected of sensitivity
Isochronous
When the crank is at the inner dead centre, in a reciprocating steam engine, then the velocity of the piston will be
Minimum
Zero
Maximum
None of these
If the radius of gyration of a compound pendulum about an axis through e.g. is more, then its frequency of oscillation will be
Less
More
Same
Data are insufficient to determine same
A mechanism consisting of four links is called a __________ mechanism.
Simple
Compound
Binary
None of these
The maximum efficiency of a screw jack is
(1 - sinφ)/(1 + sinφ)
(1 + sinφ)/(1 - sinφ)
(1 - tanφ)/(1 + tanφ)
(1 + tanφ)/(1 - tanφ)
The Bifilar suspension method is used to determine
Natural frequency of vibration
Position of balancing weights
Moment of inertia
Centripetal acceleration
The frictional torque transmitted in a flat pivot bearing with assumption of uniform pressure is _________ as compared to uniform wear.
Less
More
Same
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
The ratio of the number of teeth to the pitch circle diameter in millimetres, is called
Circular pitch
Diametral pitch
Module
None of these
In a locomotive, the resultant unbalanced force due to the two cylinders along the line of stroke, is known as
Tractive force
Swaying couple
Hammer blow
None of these
The stress induced in a body will be shear stress, when it is subjected to
Longitudinal vibrations
Transverse vibrations
Torsional vibrations
None of these