The natural frequency of free transverse vibrations due to uniformly distributed load acting over a simply supported shaft is (where δS = Static deflection of simply supported shaft due to uniformly distributed load)
0.4985/ √δS
0.5615/ √δS
0.571/ √δS
0.6253/ √δS
Correct Answer :
B. 0.5615/ √δS
Related Questions
The flank of the tooth is the surface of the tooth __________ the pitch surface.
Above
Below
At
None of these
The equation of motion for a vibrating system with viscous damping is (d²x/dt²) + (c/m).(dx/dt) + (s/m).x = 0, if the roots of the equation are __________ then the system will be under damped.
Equal
Real
Complex conjugate
None of these
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
Which of the following has sliding motion?
Crank
Connecting rod
Crank pin
Crosshead
When the two elements of a pair have __________ when in motion, it is said to a lower pair.
Line or point contact
Surface contact
Body contact
None of these
Angle of action of cam is defined as the angle
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
Moved by the cam from beginning of ascent to the termination of descent
The Grubler's criterion for determining the degrees of freedom (n) of a mechanism having plane motion is (where l = Number of links, and j = Number of binary joints)
n = (l -1) - j
n = 2(l - 1) - 2j
n = 3(l - 1) - 2j
n = 4(l - 1) - 3j
Which of the following is false statement in respect of differences between machine and structure?
Machines transmit mechanical work, whereas structures transmit forces
In machines, relative motion exists between its members, whereas same does not exist in case of structures
Machines modify movement and work, whereas structures modify forces
Efficiency of machines as well as structures is below 100%
In its simplest form, a cam mechanism consists of following number of links
1
2
3
4
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
The length of a simple pendulum which gives the same frequency as the compound pendulum, is
kG + l₁
kG² + l₁
(kG² + l₁²)/ l₁
(kG + l₁²)/ l₁
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
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
The secondary unbalanced force is maximum when the angle of inclination of the crank with the line of stroke is
0° and 90°
180° and 360°
Both (A) and (B)
None of these
The danger of breakage and vibration is maximum
Below the critical speed
Near the critical speed
Above the critical speed
None of these
The main disadvantage of the sliding pair is that it is
Bulky
Wears rapidly
Difficult to manufacture
Both (A) and (B) above
The example of higher pair is
Belt, rope and chain drives
Gears, cams
Ball and roller bearings
All of the above
The unbalanced force due to reciprocating masses
Varies in magnitude but constant in direction
Varies in direction but constant in magnitude
Varies in magnitude and direction both
Constant in magnitude and direction both
The frequency of oscillation of a torsional pendulum is
2πk/r. √(g/l)
r/2πk. √(l/g)
2πr/k. √(g/l)
r/2πk. √(g/l)
Which of the following disciplines provides study of inertia forces arising from the combined effect of the mass and the motion of the parts?
Theory of machines
Applied mechanics
Mechanisms
Kinetics
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
The periodic time of a compound pendulum is __________ when the distance between the point of suspension and the centre of gravity is equal to the radius of gyration of the body about its centre of gravity.
Zero
Minimum
Maximum
None of these
The effort of a Porter governor is equal to (where c = Percentage increase in speed, m = Mass of ball, and M = Mass on the sleeve)
c (m - M) g
c (m + M) g
c/(m + M) g
c/(m - M) g
When a rigid body is suspended vertically and it oscillates with a small amplitude under the action of the force of gravity, the body is known as
Simple pendulum
Compound pendulum
Torsional pendulum
Second's pendulum
Power 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
In a screw jack, the effort required to lower the load W is given by
P = W tan(α - φ)
P = W tan(α + φ)
P = W tan(φ - α)
P = W cos(α + φ)
The unbalanced primary forces in a reciprocating engine are
Balanced completely
Balanced partially
Balanced by secondary forces
Not balanced
When the pitching of a ship is __________ the effect of gyroscopic couple acting on it will be to move the ship towards port side.
Upward
Downward
Forward
Backward
Instantaneous center of rotation of a link in a four bar mechanism lies on
Right side pivot of this link
Left side pivot of this link
A point obtained by intersection on extending adjoining links
Cant occur
Which of the following is an example of a higher pair?
Toothed gearing
Belt and rope drive
Ball and roller bearing
All of these