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
Correct Answer :
C. Isochronous
Related Questions
For low and moderate speed engines, the cam follower should move with
Uniform velocity
Simple harmonic motion
Uniform acceleration and retardation
Cycloidal motion
The Coriolis component of acceleration acts
Along the sliding surface
Perpendicular to the sliding surface
At 45° to the sliding surface
Parallel to the sliding surface
If ω/ωn = 2, where co is the frequency of excitation and ωn is the natural frequency of vibrations, then the transmissibility of vibration will the
0.5
1
1.5
2
The tendency of a body to resist change from rest or motion is known as
Mass
Friction
Inertia
Resisting force
In Meyer's expansion valve, the expansion valve is driven by an eccentric having an angle of advance from
50°-60°
60°-70°
70°-80°
80°-90°
When two pulleys are connected by means of a cross belt drive, then both the pulleys will rotate in __________ directions.
Same
Opposite
Perpendicular
None of these
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
The component of the acceleration, parallel to the velocity of the particle, at the given instant is called
Radial component
Tangential component
Coriolis component
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
The contact ratio is the ratio of
Length of pair of contact to the circular pitch
Length of arc of contact to the circular pitch
Length of arc of approach to the circular pitch
Length of arc of recess to the circular pitch
In gramophones for adjusting the speed of the turntable, the following type of governor is commonly employed
Hartung governor
Wilson Hartnell governor
Pickering governor
Inertia governor
A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the centre of bigger gear is
2
3
4
5
If there are L number of links in a mechanism, then number of possible inversions is equal to
L + 1
L - 1
L
L + 2
The gears are termed as medium velocity gears, if their peripheral velocity is
1-3 m/s
3-15 m/s
15-30 m/s
30-50 m/s
The frictional torque transmitted in a conical pivot bearing, considering uniform wear, is
(1/2) μ W R cosec α
(2/3) μ W R cosec α
(3/4) μ W R cosec α
μ W R cosec α
The height of a Watt's governor (in metres) is equal to (where N = Speed of the arm and ball about the spindle axis)
8.95/N²
89.5/N²
895/N²
8950/N²
A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if
The sum of the two masses is equal to the total mass of body
The centre of gravity of the two masses coincides with that of the body
The sum of mass moment of inertia of the masses about their centre of gravity is equal to the mass moment of inertia of the body
All of the above
A Hartnell governor is a
Dead weight governor
Pendulum type governor
Spring loaded governor
Inertia governor
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
For an isochronous Hartnell governor (where r₁ and r₂ = Maximum and minimum radius of rotation of balls respectively, S₁ and S₂ = Maximum and minimum force exerted on the sleeve respectively, and M = Mass on the sleeve)
(m.g + S₁)/(m.g + S₂) = r₁/r₂
(m.g - S₁)/(m.g - S₂) = r₂/r₁
S₁/S₂ = r₁/r₂
S₂/S₁ = r₁/r₂
Flexible coupling is used because
It is easy to disassemble
It is easy to engage and disengage
It transmits shocks gradually
It prevents shock transmission and eliminates stress reversals
In a flat collar pivot bearing, the moment due to friction is proportional to
(r₁² - r₂²)/(r₁ - r₂)
(r₁² - r₂²)/(r₁ + r₂)
(r₁³ - r₂³)/(r₁² - r₂²)
(r₁³ - r₂³)/(r₁ - r₂)
The acceleration of a particle moving with simple harmonic motion, at any instant is given by
ωx
ω²x
ω²/x
ω³/x
Which of the following statement is correct?
For constant velocity ratio transmission between two gears, the common normal at the point of contact must always pass through a fixed point on the line joining the centres of rotation of gears.
For involute gears, the pressure angle changes with the change in centre distance between gears.
The epicyclic gear trains involve rotation of atleast one gear axis about some other gear axis.
All of the above
Which of the following statement is correct?
The primary unbalanced force is less than the secondary unbalanced force.
The primary unbalanced force is maximum twice in one revolution of the crank.
The unbalanced force due to reciprocating masses varies in magnitude and direction both.
The magnitude of swaying couple in locomotives is inversely proportional to the distance between the two cylinder centre lines
Kinematic 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
A mechanism __________ for transmitting or transforming motion.
Can be used
Cannot be used
Unpredictable
None of these
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
For a kinematic chain to be considered as mechanism
Two links should be fixed
One link should be fixed
None of the links should be fixed
There is no such criterion
A point on a link connecting double slider crank chain traces a
Ellipse
Circle
Parabola
Hyperbola