A mass of 1 kg is attached to the end of a spring with a stiffness of 0.7 N/mm. The critical damping coefficient of this system is
1.4 N-s/m
18.52 N-s/m
52.92 N-s/m
529.2 N-s/m
Correct Answer :
C. 52.92 N-s/m
Related Questions
The main disadvantage of the sliding pair is that it is
Bulky
Wears rapidly
Difficult to manufacture
Both (A) and (B) above
The included angle for the V-belt is usually
10° to 20°
20° to 30°
30° to 40°
60° to 80°
The balancing of a rigid rotor can be achieved by appropriately placing balancing masses in
A single plane
Two planes
Three planes
Four planes
Pitch point of a cam is
A point on the pitch curve having minimum pressure angle
A point on the pitch curve having maximum pressure angle
Any point on the pitch curve
Any point on the pitch circle
According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centers lie on
A triangle
A point
Two lines
A straight line
The primary unbalanced force due to inertia of reciprocating parts in a reciprocating engine is given by (where m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, θ = Angle of inclination of crank with the line of stroke, and n = Ratio of the length of connecting rod to radius of crank)
m.ω².r sinθ
m.ω².r cosθ
m.ω².r (sin 2θ/n)
m.ω².r (cos 2θ/n)
The instantaneous centres which vary with the configuration of mechanism are called
Permanent instantaneous centres
Fixed instantaneous centres
Neither fixed nor permanent instantaneous centres
None of the above
The maximum value of the pressure angle in case of cam is kept as
10°
14°
20°
30°
When a body moves with simple harmonic motion, the product of its periodic time and frequency is equal to
Zero
One
π/2
π
Rectilinear motion of piston is converted into rotary by
Cross head
Slider crank
Connecting rod
Gudgeon pin
3.The retardation of a flat faced follower when it has contact at the apex of the nose of a circular arc cam, is given by (where OQ = Distance between the centre of circular flank and centre of nose)
ω² × OQ
ω² × OQ sinθ
ω² × OQ cosθ
ω² × OQ tanθ
In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is Constant, then
Open belt drive is recommended
Crossed belt drive is recommended
Both open belt drive and crossed belt drive is recommended
The drive is recommended depending upon the torque transmitted
Torsional 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 static balancing is satisfactory for low speed rotors but with increasing speeds, dynamic balancing becomes necessary. This is because, the
Unbalanced couples are caused only at higher speeds
Unbalanced forces are not dangerous at higher speeds
Effects of unbalances are proportional to the square of the speed
Effects of unbalances are directly proportional to the speed
Whitworth quick return mechanism is obtained by inversion of
Slider crank mechanism
Kinematic chain
Five link mechanism
Roller cam mechanism
The indicator using Watt mechanism is known as
Thompson indicator
Richard indicator
Simplex indicator
Thomson indicator
Which of the following would constitute a link?
Piston, piston rod and cross head
Piston and piston rod
Piston rod and cross head
Piston, crank pin and crank shaft
A point on a link connecting double slider crank chain traces a
Ellipse
Circle
Parabola
Hyperbola
Which of the following disciplines provides study of relative motion between the parts of a machine?
Theory of machines
Applied mechanics
Mechanisms
Kinematics
Two systems shall be dynamically equivalent when
The mass of two are same
C.G. of two coincides
M.I. of two about an axis through e.g. is equal
All of the above
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
In a simple harmonic motion, the velocity vector with respect to displacement vector
Is in phase
Leads by 90°
Leads by 180°
Lags by 90°
For high speed engines, the cam follower should move with
Uniform velocity
Simple harmonic motion
Uniform acceleration and retardation
Cycloidal motion
When the body is suspended at the point of suspension, its periodic time and frequency will be ________ as compared to the body suspended at the point of percussion.
Same
Two times
Four times
None of these
The two parallel and coplanar shafts are connected by gears having teeth parallel to the axis of the shaft. This arrangement is known as
Spur gearing
Helical gearing
Bevel gearing
Spiral gearing
Bifilar suspension method is used to find the
Angular acceleration of the body
Moment of inertia of the body
Periodic time of the body
Frequency of vibration of the body
A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The radial component of the acceleration of B with respect to A, is (where vBA = Linear velocity of B with respect to A)
vBA × AB
vBA /AB
v²BA
v²BA /AB
Module of a gear is
D/T
T/D
2D/T
2T/D
The motion between a pair which takes place in __________ is known as incompletely constrained motion.
One direction only
Two directions only
More than one direction
None of these
Length of arc of contact is given by
Arc of approach - Arc of recess
Arc of approach + Arc of recess
Arc of approach / Arc of recess
Arc of approach × Arc of recess