For an involute gear, the ratio of base circle radius and pitch circle radius is equal to
sinφ
cosφ
secφ
cosecφ
Correct Answer :
B. cosφ
Related Questions
The example of completely constrained motion is a
Motion of a piston in the cylinder of a steam engine
Motion of a square bar in a square hole
Motion of a shaft with collars at each end in a circular hole
All of the above
In a four bar chain or quadric cycle chain
Each of the four pairs is a turning pair
One is a turning pair and three are sliding pairs
Two are turning pairs and two are sliding pairs
Three are turning pairs and one is a sliding pair
When the elements of a pair are kept in contact by the action of external forces, the pair is said to be a
Lower pair
Higher pair
Self-closed pair
Force-closed pair
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
If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be
Four times the first one
Same as the first one
One fourth of the first one
One and a half times the first one
A chain comprises of 5 links having 5 joints. Is it kinematic chain?
Yes
No
It is a marginal case
Data are insufficient to determine it
The equation of motion for a vibrating system with viscous damping is (d²x/dt²) + (c/m).(dx/dt) + (s/m).x = 0, if the roots of the equation are __________ then the system will be under damped.
Equal
Real
Complex conjugate
None of these
The absolute acceleration of any point P in a link about center of rotation O is
Along PO
Perpendicular to PO
At 45° to PO
None of the above
The moment on the pulley which produces rotation is called
Inertia
Momentum
Moment of momentum
Torque
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 balancing weights are introduced in planes parallel to the plane of rotation of the disturbing mass. To obtain complete dynamic balance, the minimum number of balancing weights to be introduced in different planes is
1
2
3
4
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
The arrangement is called bevel gearing, when two __________ are connected by gears.
Intersecting and coplanar shafts
Nonintersecting and non-coplanar shafts
Parallel and coplanar shafts
Parallel and non-coplanar shafts
Minimum number of teeth for involute rack and pinion arrangement for pressure angle of 20° is
18
20
30
34
The frequency of oscillation of a torsional pendulum is
2πk/r. √(g/l)
r/2πk. √(l/g)
2πr/k. √(g/l)
r/2πk. √(g/l)
In a screw jack, the effort required to lower the load W is given by
P = W tan(α - φ)
P = W tan(α + φ)
P = W tan(φ - α)
P = W cos(α + φ)
In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be (where ω = Angular speed of the system, ωn = Natural frequency of vibration of the system)
Less than unity
Equal to unity
Greater than unity
Zero
Governor is used in automobile to
Decrease the variation of speed
Maximize the fuel economy
Limit the vehicle speed
Maintain constant engine speed
A higher pair has__________.
Point contact
Surface contact
No contact
None of the above
In under damped vibrating system, the amplitude of vibration
Decreases linearly with time
Increases linearly with time
Decreases exponentially with time
Increases exponentially with time
Angle of descent of cam is defined as the angle
During which the follower returns to its initial position
Of rotation of the cam for a definite displacement of the follower
Through which the cam rotates during the period in which the follower remains in the highest position
Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
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
A shaft carrying two rotors at its ends will have
No node
One node
Two nodes
Three nodes
Pitch point on a cam is
Any point on pitch curve
The point on cam pitch curve having the maximum pressure angle
Any point on pitch circle
The point on cam pitch curve having the minimum pressure angle
A system of masses rotating in different parallel planes is in dynamic balance if the
Resultant force is equal to zero
Resultant couple is equal to zero
Resultant force and resultant couple are both equal to zero
Resultant force is numerically equal to the resultant couple, but neither of them need necessarily be zero
Scotch yoke mechanism is used to generate
Sine functions
Square roots
Logarithms
Inversions
Efficiency of a screw jack is given by
tan (α + φ)/tanα
tanα/tan (α +φ)
tan (α - φ)/tanα
tanα/tan (α - φ)
Which of the following is a higher pair?
Belt and pulley
Turning pair
Screw pair
Sliding pair
The gears are termed as medium velocity gears, if their peripheral velocity is
1-3 m/s
3-15 m/s
15-30 m/s
30-50 m/s
The following is the inversion of slider crank chain mechanism
Whitworth quick return mechanism
Hand pump
Oscillating cylinder engine
All of the above