The natural frequency of free longitudinal vibrations is equal to (where m = Mass of the body, s = Stiffness of the body, and δ = Static deflection of the body)
1/2π × √(s/m)
1/2π × √(g/δ)
0.4985/√δ
Any one of these
Correct Answer :
D. Any one of these
Related Questions
A body in motion will be subjected to coriolis acceleration when that body is
In plane rotation with variable velocity
In plane translation with variable velocity
In plane motion which is a resultant of plane translation and rotation
Restrained to rotate while sliding over another body
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
A body is said to be under forced vibrations, when
There is a reduction in amplitude after every cycle of vibration
No external force acts on a body, after giving it an initial displacement
A body vibrates under the influence of external force
None of the above
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
The Klein's diagram is useful to find
Displacement of various parts
Velocity of various parts
Acceleration of various parts
Angular acceleration of various parts
Klein's construction can be used when
Crank has a uniform angular velocity
Crank has non-uniform velocity
Crank has uniform angular acceleration
Crank has uniform angular velocity and angular acceleration
The relation between the controlling force (Fc) and radius of rotation (r) for a stable spring controlled governor is
Fc = ar + b
Fc = ar - b
Fc = ar
Fc = a/r + b
The size of cam depends upon
Base circle
Pitch circle
Prime circle
Pitch curve
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
Whirling speed of the shaft is the speed at which
Shaft tends to vibrate in longitudinal direction
Torsional vibrations occur
Shaft tends to vibrate vigorously in transverse direction
Combination of transverse and longitudinal vibration occurs
Coriolis component is encountered in
Quick return mechanism of shaper
Four bar chain mechanism
Slider crank mechanism
Both (A) and (C) above
When a ship travels in a sea, which of the effect is more dangerous
Steering
Pitching
Rolling
All of the above
Which of the following statements regarding laws governing the friction between dry surfaces are correct?
The friction force is dependent on the materials of the contact surfaces.
The friction force is directly proportional to the normal force.
The friction force is independent of me area of contact.
All of the above
Peaucelliers mechanism has
Eight links
Six links
Four links
Twelve links
In automobiles the power is transmitted from gear box to differential through
Bevel gear
Universal joint
Hooke's joint
Knuckle joint
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)
Idler pulley is used
For changing the direction of motion of the belt
For applying tension
For increasing velocity ratio
All of the above
In a steam engine, one method of obtaining the earlier cut-off with a simple slide valve is by increasing the angle of advance of the eccentric while the throw of the eccentric, steam lap and exhaust lap are kept constant. 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
A mechanism is an assemblage of
Two links
Three links
Four or more than four links
All of these
The factor which affects the critical speed of a shaft is
Diameter of disc
Span of shaft
Eccentricity
All of these
The power from the engine to the rear axle of an automobile is transmitted by means of
Worm and worm wheel
Spur gears
Bevel gears
Hooke's joint
The centrifugal tension in belts
Increases power transmitted
Decreases power transmitted
Have no effect on power transmitted
Increases power transmitted upto a certain speed and then decreases
V-belts are usually used for
Long drives
Short drives
Long and short drives
None of these
When a shaking force is transmitted through the springs, damping becomes detrimental when the ratio of its frequency to the natural frequency is greater than
0.25
0.5
1
2
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 Hartnell governor has its controlling force (Fc) given by Fc = ar + b, where r is the radius of rotation and a and b are constants. The governor becomes isochronous when
a is +ve and b = 0
a = 0 and b is +ve
a is +ve and b is -ve
a is +ve and b is also +ve
The coriolis component of acceleration exists whenever a point moves along a path that has
Linear displacement
Rotational motion
Gravitational acceleration
Tangential acceleration
The flank of the tooth is the surface of the tooth __________ the pitch surface.
Above
Below
At
None of these
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
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