The condition for correct steering of a Davis steering gear is (where α = Angle of inclination of the links to the vertical)
sinα = b/c
cosα = c/b
tanα = c/2b
cotα = c/2b
Correct Answer :
C. tanα = c/2b
Related Questions
The mechanism in which two are turning pairs and two are sliding pairs, is called a
Double slider crank chain
Elliptical trammel
Scotch yoke mechanism
All of these
For two governors A and B, the lift of sleeve of governor A is more than that of governor B, for a given fractional change in speed. It indicates that
Governor A is more sensitive than governor B
Governor B is more sensitive than governor A
Both governors A and B are equally sensitive
None of the above
In vibration isolation system, if ω/ωn > 1, then the phase difference between the transmitted force and the disturbing force is
0°
90°
180°
270°
If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be
Stable
Unstable
Isochronous
None of these
The cam follower generally used in automobile engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
Klein's construction is useful to determine
Velocity of various parts
Acceleration of various parts
Displacement of various parts
Angular acceleration of various parts
A simple spring-mass vibrating system has a natural frequency of fn. If the spring stiffness is halved and the mass is doubled, then the natural frequency will become
fn/2
2 fn
4 fn
8 fn
The motion between a pair when limited to a definite direction, irrespective of the direction of force applied, is known as
Completely constrained motion
Incompletely constrained motion
Successfully constrained motion
None of these
The radius of a friction circle for a shaft rotating inside a bearing is (where r = Radius of shaft, and tan φ = Coefficient of friction between the shaft and bearing)
r sinφ
r cosφ
r tanφ
(r/2) cosφ
The C.G. of a link in any mechanism would experience
No acceleration
Linear acceleration
Angular acceleration
Both angular and linear accelerations
When the sleeve of a Porter governor moves upwards, the governor speed
Increases
Decreases
Remain unaffected
First increases and then decreases
The product of the diametral pitch and circular pitch is equal to
1
1/π
π
2 π
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
Which of the following mechanism is obtained from lower pair?
Gyroscope
Pantograph
Valve and valve gears
All of the above
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
In a reciprocating engine, usually __________ of the reciprocating masses are balanced.
One-half
Two-third
Three-fourth
Whole
A mechanism is an assemblage of
Two links
Three links
Four or more than four links
All of these
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
A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tan φ = Coefficient of friction between the plane and the body)
P = W tan α
P = W tan (α + φ)
P = W (sin α + μ cos α)
P = W (cos α + μ sin α)
The motion of a shaft in a circular hole is an example of
Completely constrained motion
Incompletely constrained motion
Successfully constrained motion
None of these
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)
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
Which of the following would constitute a link?
Piston, piston rod and cross head
Piston and piston rod
Piston rod and cross head
Piston, crank pin and crank shaft
In a ball bearing, ball and bearing forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
Open 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
When a mass of a critically damped single degree of freedom system is deflected from its equilibrium position and released, then it will
Return to equilibrium position without oscillation
Oscillate with increasing time period
Oscillate with decreasing amplitude
Oscillate with constant amplitude
A spring controlled governor is said to be stable if the controlling force line when produced intersects the Y-axis
At the origin
Below the origin
Above the origin
Any one of these
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
The maximum fluctuation of speed is the
Difference of minimum fluctuation of speed and the mean speed
Difference of the maximum and minimum speeds
Sum of maximum and minimum speeds
Variations of speed above and below the mean resisting torque line
When the addenda on pinion and wheel is such that the path of approach and path of recess are half of their maximum possible values, then the length of the path of contact is given by (where r = Pitch circle radius of pinion, R = Pitch circle radius of wheel, and φ = Pressure angle)
[(r² + R²) cosφ]/2
[(r² + R²) sinφ]/2
[(r + R) cosφ]/2
[(r + R) sinφ]/2