At the nodal point in a shaft, the amplitude for torsional vibration will be
Minimum
Maximum
Zero
Infinity
Correct Answer :
C. Zero
Related Questions
The coriolis component of acceleration is taken into account for
Slider crank mechanism
Four bar chain mechanism
Quick return motion mechanism
All of these
In elliptical trammels
All four pairs are turning
Three pairs turning and one pair sliding
Two pairs turning and two pairs sliding
One pair turning and three pairs sliding
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)
Longitudinal vibrations are said to occur when the particles of a body moves
Perpendicular to its axis
Parallel to its axis
In a circle about its axis
None of these
The factor which affects the critical speed of a shaft is
Diameter of disc
Span of shaft
Eccentricity
All of these
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°
For S.H.M. cam, the acceleration of the follower at the ends of the stroke and aimed stroke respectively, is
Maximum and zero
Zero and maximum
Minimum and maximum
Zero and minimum
The periodic time of one oscillation for a simple pendulum is
2π. √(g/l)
(1/2π). √(g/l)
2π. √(l/g)
(1/2π). √(l/g)
When the crank is at the inner dead centre, in a reciprocating steam engine, then the velocity of the piston will be
Minimum
Zero
Maximum
None of these
In railway axle boxes, the bearing used is
Deep groove ball bearing
Double row self aligning ball bearing
Double row spherical roller bearing
Cylindrical roller bearing
Idler pulley is used
For changing the direction of motion of the belt
For applying tension
For increasing velocity ratio
All of the above
Kinematic pairs are those which have
Two elements held together mechanically
Two elements having relative motion
Two elements having Coriolis component
Minimum of two instantaneous centres
The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where l₁ and l₂ = Distance of two masses from the centre of gravity of the body, and kG = Radius of gyration of the body)
l₁ = kG
l₂ = kG
l₁l₂ = kG
l₁l₂ = kG²
For the same lift and same angle of ascent, a smaller base circle will give
A small value of pressure angle
A large value of pressure angle
There is no such relation with pressure angle
Something else
The included angle for the V-belt is usually
10° to 20°
20° to 30°
30° to 40°
60° to 80°
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
A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The total acceleration of B with respect to A will be equal to
Vector sum of radial component and coriolis component
Vector sum of tangential component and coriolis component
Vector sum of radial component and tangential component
Vector difference of radial component and tangential component
When two links are connected by a pin joint, their instantaneous centre lies
On their point of contact
At the centre of curvature
At the centre of circle
At the pin joint
The mechanism forms a structure, when the number of degrees of freedom (n) is equal to
0
1
2
-1
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
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
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 is a pendulum type governor?
Watt governor
Porter governor
Hartnell governor
None of these
When the speed of the engine fluctuates continuously above and below the mean speed, the governor is said to be
Stable
Unstable
Isochronous
Hunt
The natural frequency of free transverse vibrations due to a point load acting over a simply supported shaft is equal to (where δ = Static deflection of a simply supported shaft due to the point load)
0.4985/√δ
0.5615/√δ
0.571/√δ
0.6253/√δ
If ω/ωn is very high for a body vibrating under steady state vibrations, the phase angle for all values of damping factors, will tend to approach
0°
90°
180°
360°
The maximum or minimum value of the swaying couple is
± c.m.ω².r
± a (1 - c) m.ω².r
± (a/√2) (1 - c) m.ω².r
± 2a (1 - c) m.ω².r
In considering friction of a V-thread, the virtual coefficient of friction (μ₁) is given by
μ₁ = μ sinβ
μ₁ = μ cosβ
μ₁ = μ/sinβ
μ₁ = μ/cosβ
The Kutzbach criterion for determining the number of degrees of freedom (n) is (where l = number of links, j = number of joints and h = number of higher pairs)
n = 3(l - 1) - 2j - h
n = 2(l - 1) -2j - h
n = 3(l - 1) - 3j - h
n = 2(l - 1) - 3j - h
The indicator using Watt mechanism is known as
Thompson indicator
Richard indicator
Simplex indicator
Thomson indicator