The secondary unbalanced force is maximum __________ in one revolution of the crank.
Two times
Four times
Eight times
Sixteen times
Correct Answer :
B. Four times
Related Questions
In a Hartnell governor, the stiffness of the spring is given by (where S1 and S2 = Spring forces exerted on the sleeve at max. and min. radii of rotation, and h = Compression of the spring)
(S₁ + S₂)/h
(S₁ - S₂)/h
(S₁ + S₂)/2h
(S₁ - S₂)/2h
The velocity of any point in mechanism relative to any other point on the mechanism on velocity polygon is represented by the line
Joining the corresponding points
Perpendicular to line as per (A)
Not possible to determine with these data
At 45° to line as per (A)
The factor which affects the critical speed of a shaft is
Diameter of disc
Span of shaft
Eccentricity
All of these
When the sleeve of a Porter governor moves downwards, the governor speed
Increases
Decreases
Remain unaffected
First increases and then decreases
Typewriter constitutes
Machine
Structure
Mechanism
Inversion
A disturbing mass m₁ attached to the rotating shaft may be balanced by a single mass m₂ attached in the same plane of rotation as that of m₁, such that (where r₁ and r₂ are the radii of rotation of m₁ and m₂ respectively)
m₁r₂ = m₂r₁
m₁r₁ = m₂r₂
m₁m₂ = r₁r₂
None of these
Creep in belt drive is due to
Material of the pulley
Material of the belt
Larger size of the driver pulley
Uneven extensions and contractions due to varying tension
To connect two parallel and coplanar shafts the following type of gearing is used
Spur gear
Bevel gear
Spiral gear
None of the above
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
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 relative velocity of B with respect to A in a rigid link AB is
Parallel to AB
Perpendicular to AB
Along AB
At 45° to AB
A mechanism consisting of four links is called a __________ mechanism.
Simple
Compound
Binary
None of these
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 maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)
sin (θ + φ) + 1/ cos (θ - φ) + 1
cos (θ - φ) + 1/ sin (θ + φ) + 1
cos (θ + φ) + 1/ cos (θ - φ) + 1
cos (θ - φ) + 1/ cos (θ + φ) + 1
In a ball bearing, ball and bearing forms a
Turning pair
Rolling pair
Screw pair
Spherical pair
In a circular arc cam with roller follower, the acceleration in any position of the lift will depend only upon
Total lift, total angle of lift, minimum radius of cam and cam speed
Radius of circular arc, cam speed, location of centre of circular arc and roller diameter
Mass of cam follower linkage, spring stiffness and cam speed
Total lift, centre of gravity of the cam and cam speed
The face of the tooth is the
Surface of the top of tooth
Surface of tooth above the pitch surface
Width of tooth below the pitch surface
Width of tooth measured along the pitch circle
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
An involute pinion and gear are in mesh. If both have the same size of addendum, then there will be an interference between the
Tip of the gear tooth and flank of pinion
Tip of the pinion and flank of gear
Flanks of both gear and pinion
Tip of both gear and pinion
The frictional torque transmitted by a cone clutch is same as that of
Flat pivot bearing
Flat collar bearing
Conical pivot bearing
Truncated conical pivot bearing
In full depth involute system, the smallest number of teeth in a pinion which meshes with rack without interference is
12
16
25
32
The following is the inversion of slider crank chain mechanism
Whitworth quick return mechanism
Hand pump
Oscillating cylinder engine
All of the above
In a spring controlled governor, when the controlling force ________ as the radius of rotation increases, it is said to be a stable governor.
Remains constant
Decreases
Increases
None of these
A cam mechanism imparts following motion
Rotating
Oscillating
Reciprocating
All of the above
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
The Ackermann steering mechanism is preferred to the Davis type in automobiles because
The former is mathematically accurate
The former is having turning pair
The former is most economical
The former is most rigid
Sense of tangential acceleration of a link
Is same as that of velocity
Is opposite to that of velocity
Could be either same or opposite to velocity
Is perpendicular to that of velocity
If the damping factor for a vibrating system is unity, then the system will be
Over damped
Under damped
Critically damped
Without vibrations
V-belts are usually used for
Long drives
Short drives
Long and short drives
None of these
Ball and a Socket forms a
Turning pair
Rolling pair
Screw pair
Spherical pair