The centre distance between two meshing involute gears is equal to
Sum of base circle radii/cosφ
Difference of base circle radii/ cosφ
Sum of pitch circle radii/ cosφ
Difference of pitch circle radii/ cosφ
Correct Answer :
A. Sum of base circle radii/cosφ
Related Questions
The instantaneous centre of a rigid thin disc rolling on a plane rigid surface is located at
The centre of the disc
The point of contact
An infinite distance on the plane surface
The point on the circumference situated vertically opposite to the contact point
A Porter governor is a
Pendulum type governor
Dead weight governor
Spring loaded governor
Inertia governor
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
Which of the following would constitute a link?
Piston, piston rod and cross head
Piston and piston rod
Piston rod and cross head
Piston, crank pin and crank shaft
When a body is subjected to transverse vibrations, the stress induced in a body will be
Shear stress
Bending stress
Tensile stress
Compressive stress
Efficiency of a screw jack is given by
tan (α + φ)/tanα
tanα/tan (α +φ)
tan (α - φ)/tanα
tanα/tan (α - φ)
In a system subjected to damped forced vibrations, the ratio of maximum displacement to the static deflection is known as
Critical damping ratio
Damping factor
Logarithmic decrement
Magnification factor
A point on a link connecting double slider crank chain traces a
Ellipse
Circle
Parabola
Hyperbola
The dedendum circle diameter is equal to (where, φ = Pressure angle)
Pitch circle dia. × cosφ
Addendum circle dia. × cosφ
Clearance circle dia. × cosφ
Pitch circle dia. × sinφ
In vibration isolation system, the transmissibility will be equal to unity, for all values of damping factor, if ω/ωn is
Equal to 1
Equal to 2
Less than 2
Greater than 2
Whirling speed of the shaft is the speed at which
Shaft tends to vibrate in longitudinal direction
Torsional vibrations occur
Shaft tends to vibrate vigorously in transverse direction
Combination of transverse and longitudinal vibration occurs
When the load on the engine increases, it becomes necessary to increase the supply of working fluid and when the load decreases, less working fluid is required. The supply of the working fluid to the engine is controlled by a
D-slide valve
Governor
Meyer's expansion valve
Flywheel
In Meyer's expansion valve, the main valve is driven by an eccentric having an angle of advance from
10°-15°
15°-25°
25°-30°
30°-40°
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
When a ship travels in a sea, which of the effect is more dangerous
Steering
Pitching
Rolling
All of the above
Peaucelliers mechanism has
Eight links
Six links
Four links
Twelve links
In a reciprocating engine, usually __________ of the reciprocating masses are balanced.
One-half
Two-third
Three-fourth
Whole
A spring controlled governor is found unstable. It can be made stable by
Increasing the spring stiffness
Decreasing the spring stiffness
Increasing the ball mass
Decreasing the ball mass
The maximum or minimum value of the swaying couple is
± c.m.ω².r
± a (1 - c) m.ω².r
± (a/√2) (1 - c) m.ω².r
± 2a (1 - c) m.ω².r
A mechanism consisting of four links is called a __________ mechanism.
Simple
Compound
Binary
None of these
Which of the following is an example of a higher pair?
Toothed gearing
Belt and rope drive
Ball and roller bearing
All of these
In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is Constant, then
Open belt drive is recommended
Crossed belt drive is recommended
Both open belt drive and crossed belt drive is recommended
The drive is recommended depending upon the torque transmitted
In a coupling rod of a locomotive, each of the four pairs is a ________ pair.
Sliding
Turning
Rolling
Screw
For the brake to be self locking, the force P at C shown in the below figure, should 
Be zero
Act in upward direction
Act in downward direction
None of these
The sensitiveness of the governor __________ as the speed range decreases.
Remains unaffected
Decreases
Increases
None of these
The centre of percussion is below the centre of gravity of the body and is at a distance equal to
h/kG
h²/kG
kG²/h
h × kG
Hart mechanism has
Eight links
Six links
Four links
Twelve links
The steering of a ship means
Movement of a complete ship up and down in vertical plane about transverse axis
Turning of a complete ship in a curve towards right or left, while it moves forward
Rolling of a complete ship sideways
None of the above
A rigid body possesses ________degrees of freedom
One
Two
Four
Six
A cam with a roller follower would constitute following type of pair
Lower pair
Higher pair
Open pair
Close pair