The unbalanced primary forces in a reciprocating engine are
Balanced completely
Balanced partially
Balanced by secondary forces
Not balanced
Correct Answer :
B. Balanced partially
Related Questions
The partial balancing of reciprocating parts in locomotives produces
Hammer blow
Swaying couple
Variation in tractive force along the line of stroke
All of the above
The frictional torque transmitted in a flat collar bearing, considering uniform wear, is (where r₁ and r₂ = External and internal radii of collar respectively)
(1/2) μ W (r₁ + r₂)
(2/3) μ W (r₁ + r₂)
(1/2) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]
A shaft carrying three rotors will have
No node
One node
Two nodes
Three nodes
Coriolis component is encountered in
Quick return mechanism of shaper
Four bar chain mechanism
Slider crank mechanism
Both (A) and (C) above
The lower pairs are __________ pairs.
Self-closed
Force-closed
Friction closed
None of these
The fundamental equation for correct steering is (where φ and α = Angle through which the axis of the outer wheel and inner wheel turns respectively, c = Distance between the pivots of the front axles, and d = Wheel base)
sinφ + sinα = b/c
cosφ - sinα = c/b
cotφ - cotα = c/b
tanφ + cotα = b/c
If there are L number of links in a mechanism, then number of possible inversions is equal to
L + 1
L - 1
L
L + 2
The unbalanced force due to revolving 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 example of spherical pair is
Bolt and nut
Lead screw of a lathe
Ball and socket joint
Ball bearing and roller bearing
Which of the following statement is wrong?
The difference between the maximum and minimum energies is called maximum fluctuation of energy
The coefficient of fluctuation of speed is the ratio of maximum fluctuation of speed to the mean speed
The variations of energy above and below the mean resisting torque line is known as fluctuation of energy
None of the above
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 this equation are real, then the system will be
Over-damped
Under damped
Critically damped
Without vibrations
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
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
It is required to connect two parallel shafts, the distance between whose axes is small and variable. The shafts are coupled by
Universal joint
Knuckle joint
Oldham's coupling
Flexible coupling
ABCD is a four bar mechanism in which AB = 310 mm and CD = 450 mm. AB and CD are both perpendicular to the fixed link AD, as shown in the below figure. If the velocity of B at this condition is v. Then the velocity of C is 
v
(2/3). v
(3/2). v
(9/4). v
For high speed engines, the cam follower should move with
Uniform velocity
Simple harmonic motion
Uniform acceleration and retardation
Cycloidal motion
The frictional torque transmitted in a truncated conical pivot bearing, considering uniform wear, is
(1/2). μ W cosec α (r₁ + r₂)
(2/3).μ W cosec α (r₁ + r₂)
(1/2). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
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)]
The absolute acceleration of any point P in a link about center of rotation O is
Along PO
Perpendicular to PO
At 45° to PO
None of the above
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
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)
The frictional torque transmitted in a conical pivot bearing, considering uniform pressure, is (where R = Radius of shaft, and α = Semi-angle of the cone)
(1/2) μ W R cosecα
(2/3) μ W R cosecα
(3/4) μ W R cosecα
μ W R cosecα
A Porter governor is a
Pendulum type governor
Dead weight governor
Spring loaded governor
Inertia governor
Klein's construction can be used to determine acceleration of various parts when the crank is at
Inner dead centre
Outer dead centre
Right angles to the link of the stroke
All of the above
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 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
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
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
When the nature of contact between the elements of a pair is such that one element can turn about the other by screw threads, the pair is known as a
Screw pair
Spherical pair
Turning pair
Sliding pair
If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be
Four times the first one
Same as the first one
One fourth of the first one
One and a half times the first one