The cam follower generally used in aircraft engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
Correct Answer :
D. Roller follower
Related Questions
In a system subjected to damped forced vibrations, the ratio of maximum displacement to the static deflection is known as
Critical damping ratio
Damping factor
Logarithmic decrement
Magnification factor
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
The coriolis component of acceleration leads the sliding velocity by
45°
90°
135°
180°
An involute pinion and gear are in mesh. If both have the same size of addendum, then there will be an interference between the
Tip of the gear tooth and flank of pinion
Tip of the pinion and flank of gear
Flanks of both gear and pinion
Tip of both gear and pinion
The Hooke's joint consists of:
Two forks
One fork
Three forks
Four forks
When brakes are applied to all the four wheels of a moving car, the distance travelled by the car before it is brought to rest, will be
Maximum
Minimum
Zero
None of these
In a four stroke I.C. engine, the turning moment during the compression stroke is
Positive throughout
Negative throughout
Positive during major portion of the stroke
Negative during major portion of the stroke
Two pulleys of radii r₁ and r₂ and at distance x apart are connected by means of an open 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
V-belts are usually used for
Long drives
Short drives
Long and short drives
None of these
The size of a gear is usually specified by
Pressure angle
Circular pitch
Diametral pitch
Pitch circle diameter
The advantage of the piston valve over the slide valve is that in the former case
Wear is less
Power absorbed is less
Both wear and power absorbed are low
The pressure developed being high provides tight sealing
Two systems shall be dynamically equivalent when
The mass of two are same
C.G. of two coincides
M.I. of two about an axis through e.g. is equal
All of the above
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
The Klein's method of construction for reciprocating engine mechanism
Is a simplified version of instantaneous centre method
Utilises a quadrilateral similar to the diagram of mechanism for reciprocating engine
Enables determination of coriolis component
Is based on the acceleration diagram
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
Which of the following is an open pair?
Ball and socket joint
Journal bearing
Lead screw and nut
Cam and follower
In steady state forced vibrations, the amplitude of vibrations at resonance is __________ damping coefficient.
Equal to
Directly proportional to
Inversely proportional to
Independent of
The example of lower pair is
Shaft revolving in a bearing
Straight line motion mechanisms
Automobile steering gear
All of the above
In a mechanism, the fixed instantaneous centres are those centres which
Remain in the same place for all configurations of the mechanism
Vary with the configuration of the mechanism
Moves as the mechanism moves, but joints are of permanent nature
None of the above
With single Hooke's joint it is possible to connect two shafts, the axes of which have an angular misalignment up to
10°
20°
30°
40°
Whitworth quick return mechanism is obtained by inversion of
Slider crank mechanism
Kinematic chain
Five link mechanism
Roller cam mechanism
When a slider moves on a fixed link having curved surface, their instantaneous centre lies
On their point of contact
At the centre of curvature
At the centre of circle
At the pin joint
The tractive force in a locomotive with two cylinders is given by (where c = Fraction of reciprocating parts per cylinder, m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, and θ = Angle of inclination of crank to the line of stroke)
m.ω².r cosθ
c.m.ω².r sinθ
(1 - c).m.ω².r (cosθ - sinθ)
m.ω².r (cosθ - sinθ)
In a four-bar chain it is required to give an oscillatory motion to the follower for a continuous rotation of the crank. For the lengths of 50 mm of crank and 70 mm of the follower, determine theoretical maximum length of coupler. The minimum length of the coupler will be
45 mm
Slightly less than 45 mm
Slightly more than 45 mm
95 mm
The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
Structure
Machine
Inversion
Compound mechanism
The example of spherical pair is
Bolt and nut
Lead screw of a lathe
Ball and socket joint
Ball bearing and roller bearing
The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the left. The effect of gyroscopic couple on the aeroplane will be
To dip the nose and tail
To raise the nose and tail
To raise the nose and dip the tail
To dip the nose and raise the tail
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
Crowning on pulleys helps
In increasing velocity ratio
In decreasing the slip of the belt
For automatic adjustment of belt position so that belt runs centrally
Increase belt and pulley life
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)