The secondary 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)
Correct Answer :
D. m.ω².r (cos 2θ/n)
Related Questions
The load cup of a screw jack is made separate from the head of the spindle to
Enhance the load carrying capacity of the jack
Reduce the effort needed for lifting the working load
Reduce the value of frictional torque required to be countered for lifting the load
Prevent the rotation of load being lifted
A kinematic chain is known as a mechanism when
None of the links is fixed
One of the links is fixed
Two of the links are fixed
None of these
Any point on a link connecting double slider crank chain will trace a
Straight line
Circle
Ellipse
Parabola
The rotor of a ship rotates in clockwise direction when viewed from stern and the ship takes a left turn. The effect of gyroscopic couple acting on it will be
To raise the bow and stern
To lower the bow and stern
To raise the bow and lower the stern
To raise the stern and lower the bow
The lead screw of a lathe with nut forms a
Rolling pair
Sliding pair
Screw pair
Turning pair
In locomotives, the ratio of the connecting rod length to me crank radius is kept very large in order to
Minimise the effect of primary forces
Minimise the effect of secondary forces
Have perfect balancing
To start the locomotive quickly
An automobile steering gear is an example of
Sliding pair
Rolling pair
Lower pair
Higher pair
An eccentric sheave pivoted at one point rotates and transmits oscillatory motion to a link whose one end is pivoted and other end is connected to it. This mechanism has
2 links
3 links
4 links
5 links
In the below figure, PC is the connecting rod and OC is the crank making an angle θ with the line of stroke PO and rotates with uniform angular velocity at ω rad/s. The Klien's acceleration diagram for determining the acceleration of the piston P is shown by quadrilateral CQNO, if N coincides with O, then 
Acceleration and velocity of the piston P is zero
Acceleration and velocity of the piston P is maximum
Acceleration of the piston P is zero and its velocity is maximum
Acceleration of the piston P is maximum and its velocity is zero
When one of the links of a kinematic chain is fixed, the chain is known as a
Structure
Mechanism
Inversion
Machine
A cam mechanism imparts following motion
Rotating
Oscillating
Reciprocating
All of the above
In a drag link quick return mechanism, the shortest link is always fixed. The sum of the shortest and longest link is
Equal to sum of other two
Greater than sum of other two
Less than sum of other two
There is no such relationship
Lower 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
A Porter governor is a
Pendulum type governor
Dead weight governor
Spring loaded governor
Inertia governor
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
A disc is a spinning with an angular velocity ω rad/s about the axis of spin. The couple applied to the disc causing precession will be (where I = Mass moment of inertia of the disc, and ωP = Angular velocity of precession of the axis of spin)
(1/2).Iω²
Iω²
(1/2). I ω ωP
I ω ωP
The equation of free vibrations of a system is (d²x/dt²) +36 π²x, its natural frequency is
3 Hz
3π Hz
6 Hz
6π Hz
The rotating shafts tend to vibrate violently at whirling speeds because
The system is unbalanced
Bearing centre line coincides with the axis
The shafts are rotating at very high speeds
Resonance is caused due to the heavy mass of the rotor
To obviate axial thrust, following gear drive is used
Double helical gears having opposite teeth
Double helical gears having identical teeth
Single helical gear in which one of the teeth of helix angle a is more
Mutter gears
When a body is subjected to transverse vibrations, the stress induced in a body will be
Shear stress
Bending stress
Tensile stress
Compressive stress
The magnitude of linear velocity of a point B on a link AB relative to point A is (Where ω = Angular velocity of the link AB)
ω × AB
ω × (AB)²
ω² × AB
(ω × AB)²
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°
Coriolis component is encountered in
Quick return mechanism of shaper
Four bar chain mechanism
Slider crank mechanism
Both (A) and (C) above
The main disadvantage of the sliding pair is that it is
Bulky
Wears rapidly
Difficult to manufacture
Both (A) and (B) above
Throw of a cam is the maximum distance of the follower from
Base circle
Pitch circle
Root circle
Prime circle
Crowning on pulleys helps
In increasing velocity ratio
In decreasing the slip of the belt
For automatic adjustment of belt position so that belt runs centrally
Increase belt and pulley life
The frictional torque transmitted in a conical pivot bearing, considering uniform wear, is
(1/2) μ W R cosec α
(2/3) μ W R cosec α
(3/4) μ W R cosec α
μ W R cosec α
The cam and follower is an example of
Sliding pair
Rolling pair
Lower pair
Higher pair
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
Which gear train is used for higher velocity ratios in a small space?
Simple gear train
Compound gear train
Reverted gear train
Epicyclic gear train