In a simple train of wheels, the velocity ratio __________ the intermediate wheels.
Depends upon
Is independent of
Either A or B
None of these
Correct Answer :
B. Is independent of
Related Questions
The pressure angle of a cam depends upon
Offset between centre lines of cam and follower
Lift of follower
Angle of ascent
All of the above
The pair is known as a higher pair, when the relative motion between the elements of a pair is
Turning only
Sliding only
Rolling only
Partly turning and partly sliding
If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be
Four times the first one
Same as the first one
One fourth of the first one
One and a half times the first one
In a reciprocating steam engine, which of the following forms a kinematic link?
Cylinder and piston
Piston rod and connecting rod
Crankshaft and flywheel
Flywheel and engine frame
The face of the tooth is the
Surface of the top of tooth
Surface of tooth above the pitch surface
Width of tooth below the pitch surface
Width of tooth measured along the pitch circle
In a Hartnell governor, the lift of the sleeve is given by (where r₁ and r₂ = Max. and min. radii of rotation, x = Length of ball arm of the lever, and y = Length of sleeve arm of the lever)
(r₁ + r₂) (y/x)
(r₁ + r₂) (x/y)
(r₁ - r₂) (y/x)
(r₁ - r₂) (x/y)
Effort of a governor is the
Mean force exerted at the sleeve for a given percentage change of speed
Workdone at the sleeve for maximum equilibrium speed
Mean force exerted at the sleeve for maximum equilibrium speed
None of the above
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
A shaft has an attached disc at the centre of its length. The disc has its centre of gravity located at a distance of 2 mm from the axis of the shaft. When the shaft is allowed to vibrate in its natural bow-shaped mode, it has a frequency of vibration of 10 rad/s. When the shaft is rotated at 300 r.p.m., it will whirl with a radius of
2 mm
2.22 mm
2.50 mm
3.0 mm
In a reciprocating steam engine, when the crank has turned from inner dead centre through an angle θ, the angular velocity of the connecting rod is given by
ω sinθ/(n² - sin²θ)1/2
ω cosθ/(n² - cos²θ)1/2
ω sinθ/(n² - cos²θ)1/2
ω cosθ/(n² - sin²θ)1/2
The total number of instantaneous centres for a mechanism consisting of n links are
n/2
n
n - 1
n(n - 1)/2
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.
In locomotives, the ratio of the connecting rod length to me crank radius is kept very large in order to
Minimise the effect of primary forces
Minimise the effect of secondary forces
Have perfect balancing
To start the locomotive quickly
The component of the acceleration, perpendicular to the velocity of the particle, at the given instant is called
Radial component
Tangential component
Coriolis component
None of these
Elements of pairs held together mechanically is known as
Closed pair
Open pair
Mechanical pair
Rolling pair
The main disadvantage of the sliding pair is that it is
Bulky
Wears rapidly
Difficult to manufacture
Both (A) and (B) above
Tangential acceleration direction is
Along the angular velocity
Opposite to angular velocity
May be any one of these
Perpendicular to angular velocity
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
In a steam engine, the earlier cut-off with a simple slide valve may be obtained by increasing the steam lap and the angle of advance of the eccentric but keeping constant the travel and lead of the valve, this method will
Cause withdrawing or throttling of steam
Reduce length of effective stroke of piston
Reduce maximum opening of port to steam
All of these
The mechanism consisting of three turning pairs and one sliding pair, is called a
Single slider crank chain
Whitworth quick return motion mechanism
Crank and slotted lever quick return motion mechanism
All of the above
A Porter governor is a
Pendulum type governor
Dead weight governor
Spring loaded governor
Inertia governor
In a ball bearing, ball and bearing forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
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
Klein's construction can be used to determine acceleration of various parts when the crank is at
Inner dead centre
Outer dead centre
Right angles to the link of the stroke
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
If D₁ and D₂ be the diameters of driver and driven pulleys, then belt speed is proportional to
D₁/D₂
D₂/D₁
D₁.D₂
D₁
The factional torque for square thread at the mean radius r while raising load W is given by
T = W.r tan(φ - α)
T = W.r tan(φ + α)
T = W.r tanα
T = W.r tanφ
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)
Ackermann steering gear consists of
Sliding pairs
Turning pairs
Rolling pairs
Higher pairs
V-belts are usually used for
Long drives
Short drives
Long and short drives
None of these