The size of a gear is usually specified by
Pressure angle
Circular pitch
Diametral pitch
Pitch circle diameter
Correct Answer :
D. Pitch circle diameter
Related Questions
The radial distance of a tooth from the pitch circle to the bottom of the tooth is called
Dedendum
Addendum
Clearance
Working depth
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
Shaft revolving in a bearing is the following type of pair
Lower pair
Higher pair
Spherical pair
Cylindrical pair
The swaying couple is due to the
Primary unbalanced force
Secondary unbalanced force
Two cylinders of locomotive
Partial balancing
When the sleeve of a Porter governor moves upwards, the governor speed
Increases
Decreases
Remain unaffected
First increases and then decreases
Which of the following statement is correct for involute gears?
The interference is inherently absent.
The variation in centre distance of shafts increases radial force.
A convex flank is always in contact with concave flank.
The pressure angle is constant throughout the teeth engagement.
A Porter governor is a
Pendulum type governor
Dead weight governor
Spring loaded governor
Inertia governor
Any point on a link connecting double slider crank chain will trace a
Straight line
Circle
Ellipse
Parabola
Which gear is used for connecting two coplanar and intersecting shafts?
Spur gear
Helical gear
Bevel gear
None of the above
The frictional torque transmitted by a disc or plate clutch is same as that of
Flat pivot bearing
Flat collar bearing
Conical pivot bearing
Truncated conical pivot bearing
The ratio of height of Porter governor (when length of arms and links are equal) to the height of Watt's governor is (where m = Mass of the ball, and M = Mass on the sleeve)
m/(m + M)
M/(m + M)
(m + M)/m
(m + M)/M
If ω/ωn is very low for a body vibrating under steady state vibrations, the phase angle for all values of damping factors, will tend to approach
0°
90°
180°
360°
When the pitching of a ship is __________ the effect of gyroscopic couple acting on it will be to move the ship towards port side.
Upward
Downward
Forward
Backward
The displacement of the D-slide valve is __________ the steam lap by a distance known as lead of the valve.
Greater than
Less than
Equal to
None of these
The maximum frictional force, which comes into play, when a body just begins to slide over the surface of the other body, is known as
Static friction
Dynamic friction
Limiting friction
Coefficient of friction
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
Which of the following disciplines provides study of relative motion between the parts of a machine?
Theory of machines
Applied mechanics
Mechanisms
Kinematics
The component of the acceleration, perpendicular to the velocity of the particle, at the given instant is called
Radial component
Tangential component
Coriolis component
None of these
The flank of the tooth is the surface of the tooth __________ the pitch surface.
Above
Below
At
None of these
The velocity of the rubbing surface __________ with the distance from the axis of the bearing.
Increases
Decreases
Remain same
None of these
The static friction
Bears a constant ratio to the normal reaction between the two surfaces
Is independent of the area of contact, between the two surfaces
Always acts in a direction, opposite to that in which the body tends to move
All of the above
For high speed engines, the cam follower should move with
Uniform velocity
Simple harmonic motion
Uniform acceleration and retardation
Cycloidal motion
When a point moves along a straight line, its acceleration will have
Radial component only
Tangential component only
Coriolis component only
Radial and tangential components both
The power transmitted by a belt is maximum when the maximum tension in the belt is _________ of centrifugal tension.
One-third
Two-third
Double
Three times
The primary 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)
The axis of precession is __________ to the plane in which the axis of spin is going to rotate.
Parallel
Perpendicular
Both A and B
None of these
The relation l = (2/3).(j + 2) apply only to kinematic chains in which lower pairs are used. This may be used to kinematic chains in which higher pairs are used, but each higher pair may be taken as equivalent to
One lower pair and two additional links
Two lower pairs and one additional link
Two lower pairs and two additional links
Any one of these
The example of higher pair is
Belt, rope and chain drives
Gears, cams
Ball and roller bearings
All of the above
The mechanism in which two are turning pairs and two are sliding pairs, is called a
Double slider crank chain
Elliptical trammel
Scotch yoke mechanism
All of these
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