The two elements of a pair are said to form a higher pair, when they
Have a surface contact when in motion
Have a line or point contact when in motion
Are kept in contact by the action of external forces, when in motion
Permit relative motion
Correct Answer :
B. Have a line or point contact when in motion
Related Questions
A slider moves at a velocity v on a link revolving at ω rad/s. The coriolis component of acceleration is
ωv
2ωv
ω²v
2ωv²
Coriolis component is encountered in
Quick return mechanism of shaper
Four bar chain mechanism
Slider crank mechanism
Both (A) and (C) above
In a locomotive, the maximum magnitude of the unbalanced force along the perpendicular to the line of stroke, is known as
Tractive force
Swaying couple
Hammer blow
None of these
According to Kennedy's theorem, if three bodies move relatively to each other, their instantaneous centres will lie on a
Straight line
Parabolic curve
Triangle
Rectangle
The contact ratio is the ratio of
Length of pair of contact to the circular pitch
Length of arc of contact to the circular pitch
Length of arc of approach to the circular pitch
Length of arc of recess to the circular pitch
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 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
The following is the inversion of slider crank chain mechanism
Whitworth quick return mechanism
Hand pump
Oscillating cylinder engine
All of the above
The method of direct and reverse cranks is used in engines for
The control of speed fluctuations
Balancing of forces and couples
Kinematic analysis
Vibration analysis
In a radial cam, the follower moves
In a direction perpendicular to the cam axis
In a direction parallel to the cam axis
In any direction irrespective of the cam axis
Along the cam axis
A system in dynamic balance implies that
The system is critically damped
There is no critical speed in the system
The system is also statically balanced
There will absolutely no wear of bearings
In gears, interference takes place when
The tip of a tooth of a mating gear digs into the portion between base and root circles
Gears do not move smoothly in the absence of lubrication
Pitch of the gears is not same
Gear teeth are undercut
Typewriter constitutes
Machine
Structure
Mechanism
Inversion
When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the ________ pulley must be taken into consideration.
Smaller
Larger
Either A or B
None of these
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
The maximum fluctuation of speed is the
Difference of minimum fluctuation of speed and the mean speed
Difference of the maximum and minimum speeds
Sum of maximum and minimum speeds
Variations of speed above and below the mean resisting torque line
A rigid body possesses ________degrees of freedom
One
Two
Four
Six
The frictional torque transmitted in a flat pivot bearing with assumption of uniform pressure is _________ as compared to uniform wear.
Less
More
Same
None of these
With single Hooke's joint it is possible to connect two shafts, the axes of which have an angular misalignment up to
10°
20°
30°
40°
When a mass of a critically damped single degree of freedom system is deflected from its equilibrium position and released, then it will
Return to equilibrium position without oscillation
Oscillate with increasing time period
Oscillate with decreasing amplitude
Oscillate with constant amplitude
In its simplest form, a cam mechanism consists of following number of links
1
2
3
4
The D-slide valve is also known as
Inside admission valve
Outside admission valve
Piston slide valve
None of these
Kinematic 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 completely constrained motion can be transmitted with.
1 link with pin joints
2 links with pin joints
3 links with pin joints
4 links with pin joints
The main disadvantage of the sliding pair is that it is
Bulky
Wears rapidly
Difficult to manufacture
Both (A) and (B) above
A rotary internal combustion engine has __________ cylinders.
Four
Five
Six
Seven
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
The two elements of a pair are said to form a _________ when they permit relative motion between them.
Open pair
Kinematic pair
Sliding pair
None of these
The contact ratio is given by
(Length of the path of approach)/(Circular pitch)
(Length of path of recess)/(Circular pitch)
(Length of the arc of contact)/(Circular pitch)
(Length of the arc of approach)/cosφ
Elements of pairs held together mechanically is known as
Closed pair
Open pair
Mechanical pair
Rolling pair