The acceleration of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by
ω² R cosθ
ω² (R - r₁) cosθ
ω² (R - r₁) sinθ
ω² r₁ sinθ
Correct Answer :
B. ω² (R - r₁) cosθ
Related Questions
If the number of links in a mechanism is equal to l, then the numbers of possible inversions are equal to
l - 2
l - 1
l
l + 1
In a screw jack, the effort required to lift the load W is given by (where α = Helix angle, and φ = Angle of friction)
P = W tan(α - φ)
P = W tan(α + φ)
P = W tan(φ - α)
P = W cos(α + φ)
The velocity of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by (where ω = Angular velocity of the cam shaft)
ω (r₁ r₂) sinθ
ω (r₁ + r₂) sinθ sec2θ
ω (r₁ r₂) cosθ
ω (r₁ + r₂) cosθ cosec2θ
A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tan φ = Coefficient of friction between the plane and the body)
P = W tan α
P = W tan (α + φ)
P = W (sin α + μ cos α)
P = W (cos α + μ sin α)
In a reciprocating engine, usually __________ of the reciprocating masses are balanced.
One-half
Two-third
Three-fourth
Whole
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%
The static friction
Bears a constant ratio to the normal reaction between the two surfaces
Is independent of the area of contact, between the two surfaces
Always acts in a direction, opposite to that in which the body tends to move
All of the above
In a four stroke I.C. engine, the turning moment during the compression stroke is
Positive throughout
Negative throughout
Positive during major portion of the stroke
Negative during major portion of the stroke
The secondary unbalanced force is __________ the primary unbalanced force.
One-half
Two-third
n times
1/n times
In vibration isolation system, if ω/ωn > 1, then the phase difference between the transmitted force and the disturbing force is
0°
90°
180°
270°
If some links are connected such that motion between them can take place in more than one direction, it is called
Incompletely constrained motion
Partially constrained motion
Completely constrained motion
Successfully constrained motion
Which of the following is a turning pair?
Piston and cylinder of a reciprocating steam engine
Shaft with collars at both ends fitted into a circular hole
Lead screw of a lathe with nut
Ball and a socket joint
The type of coupling used to join two shafts whose axes are neither in same straight line nor parallel, but intersect is
Flexible coupling
Universal coupling
Chain coupling
Oldham's coupling
In order to balance the reciprocating masses,
Primary forces and couples must be balanced
Secondary forces and couples must be balanced
Both (A) and (B)
None of these
The equation of motion for a single degree of freedom system with viscous damping is 4(dx²/dt²) + 9(dx/dt) + 16x. The damping ratio of the system is
9/8
9/82
9/16
9/128
The velocity of a body moving with simple harmonic motion is __________ at the mean position.
Zero
Minimum
Maximum
None of these
A system of masses rotating in different parallel planes is in dynamic balance if the
Resultant force is equal to zero
Resultant couple is equal to zero
Resultant force and resultant couple are both equal to zero
Resultant force is numerically equal to the resultant couple, but neither of them need necessarily be zero
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 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
A torsional system with discs of moment of inertia I₁ and I₂ as shown in the below figure, is gear driven such that the ratio of speed of shaft B to shaft A is 'G'. Neglecting the inertia of gears, the equivalent inertia of disc on shaft B at the speed of shaft A is equal to 
G.I₂
G².I₂
I₂/G
I₂/G²
Any point on a link connecting double slider crank chain will trace a
Straight line
Circle
Ellipse
Parabola
If the radius of gyration of a compound pendulum about an axis through e.g. is more, then its frequency of oscillation will be
Less
More
Same
Data are insufficient to determine same
Throw of a cam is the maximum distance of the follower from
Base circle
Pitch circle
Root circle
Prime circle
Balancing of rotating and reciprocating parts of an engine is necessary when it runs at
Slow speed
Moderate speed
Highs peed
Any one of these
The frictional torque transmitted in a truncated conical pivot bearing, considering uniform pressure, is
(1/2). μ W cosecα (r₁ + r₂)
(2/3). μ W cosecα (r₁ + r₂)
(1/2). μ W cosecα [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3). μ W cosecα [(r₁³ - r₂³)/(r₁² - r₂²)]
Critical damping is a function of
Mass and stiffness
Mass and damping coefficient
Mass and natural frequency
Damping coefficient and natural frequency
The tractive force in a locomotive with two cylinders is given by (where c = Fraction of reciprocating parts per cylinder, m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, and θ = Angle of inclination of crank to the line of stroke)
m.ω².r cosθ
c.m.ω².r sinθ
(1 - c).m.ω².r (cosθ - sinθ)
m.ω².r (cosθ - sinθ)
The example of successfully constrained motion is a
Motion of an I.C. engine valve
Motion of the shaft between a footstep bearing
Piston reciprocating inside an engine cylinder
All of the above
For fluctuating loads, well suited bearing is
Ball bearing
Roller bearing
Needle roller bearing
Thrust bearing
The displacement of the D-slide valve is __________ the steam lap by a distance known as lead of the valve.
Greater than
Less than
Equal to
None of these