Which of the following mechanisms produces mathematically an exact straight line motion?
Grasshopper mechanism
Watt mechanism
Peaucellier's mechanism
Tchebicheff mechanism
Correct Answer :
C. Peaucellier's mechanism
Related Questions
The frequency of oscillation at compared to earth will be
6 times more
6 times less
2.44 times more
2.44 times less
Which of the following statement is correct?
The periodic time of a particle moving with simple harmonic motion is the time taken by a particle for one complete oscillation.
The periodic time of a particle moving with simple harmonic motion is directly proportional to its angular velocity.
The velocity of a particle moving with simple harmonic motion is zero at the mean position.
The acceleration of the particle moving with simple harmonic motion is maximum at the mean position.
The frequency of oscillation of a torsional pendulum is
2πk/r. √(g/l)
r/2πk. √(l/g)
2πr/k. √(g/l)
r/2πk. √(g/l)
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
In gears, interference takes place when
The tip of a tooth of a mating gear digs into the portion between base and root circles
Gears do not move smoothly in the absence of lubrication
Pitch of the gears is not same
Gear teeth are undercut
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
The distance by which the __________ of the D-slide valve overlaps the steam port is called exhaust lap.
Inner edge
Outer edge
Corners
None of these
When the sleeve of a Porter governor moves downwards, the governor speed
Increases
Decreases
Remain unaffected
First increases and then decreases
A Hartnell governor is a
Dead weight governor
Pendulum type governor
Spring loaded governor
Inertia governor
The swaying couple is due to the
Primary unbalanced force
Secondary unbalanced force
Two cylinders of locomotive
Partial balancing
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 frictional torque transmitted by a cone clutch is same as that of
Flat pivot bearing
Flat collar bearing
Conical pivot bearing
Truncated conical pivot bearing
A watt's governor can work satisfactorily at speeds from
60 to 80 r.p.m.
80 to 100 r.p.m.
100 to 200 r.p.m.
200 to 300 r.p.m.
Two pulleys of radii r₁ and r₂ and at distance x apart are connected by means of a cross belt drive. The length of the belt is
π (r₁ + r₂) + [(r₁ + r₂)²/x] + 2x
π (r₁ + r₂) + [(r₁ - r₂)²/x] + 2x
π (r₁ - r₂) + [(r₁ - r₂)²/x] + 2x
π (r₁ - r₂) + [(r₁ + r₂)²/x] + 2x
One end of a helical spring is fixed while the other end carries the load W which moves with simple harmonic motion. The frequency of motion is given by (where δ = Deflection of the spring)
2π. √(g/δ)
1/2π. √(g/δ)
2π. √(δ/g)
1/2π. √(δ/g)
Angle of descent 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 the highest position
Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
Which type of gearing is used in steering system of an automobile?
Rack and pinion
Worm and wheel
Spiral gears
None of the above
In a coupling rod of a locomotive, each of the four pairs is a ________ pair.
Sliding
Turning
Rolling
Screw
For a twin cylinder V-engine, the crank positions for primary reverse cranks and secondary direct cranks are shown in the below figure. The engine is a 
30° V-engine
60° V-engine
120° V-engine
150° V-engine
The cam and follower is an example of
Sliding pair
Rolling pair
Lower pair
Higher pair
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
The number of links in pantograph mechanism is equal to
2
3
4
5
The displacement of the reciprocating roller follower, when it has contact with the straight flanks of the tangent cam, is given by (where r₁ = Minimum radius of the cam, r₂ = Radius of the roller follower, and θ = Angle turned by the cam from the beginning of the follower displacement)
(r₁ - r₂) (1 - cosθ)
(r₁ + r₂) (1 + cosθ)
(r₁ - r₂) [(1 - cosθ)/cos θ]
(r₁ + r₂) [(1 - cosθ)/cos θ]
The velocity of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by (where ω = Angular velocity of the cam shaft)
ω (r₁ r₂) sinθ
ω (r₁ + r₂) sinθ sec2θ
ω (r₁ r₂) cosθ
ω (r₁ + r₂) cosθ cosec2θ
In higher pair, the relative motion is
Purely turning
Purely sliding
Purely rotary
Combination of sliding and turning
Which of the following is an open pair?
Journal bearing
Ball and Socket joint
Leave screw and nut
None of the above
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
Which of the following statement is correct as regard to the difference between a machine and a structure?
The parts of a machine move relative to one another, whereas the members of a structure do not move relative to one another
The links of a machine may transmit both power and motion, whereas the members of a structure transmit forces only
A machine transforms the available energy into some useful work, whereas in a structure no energy is transformed into useful work
All of the above
The contact ratio for gears is
Zero
Less than one
Greater than one
Infinity
Ackermann steering gear consists of
Sliding pairs
Turning pairs
Rolling pairs
Higher pairs