The expression 0.175 - 0.841/T is the Lewis form factor for
14 ½° composite and full depth involute system
20° full depth involute system
20° stub system
None of the above
Correct Answer :
C. 20° stub system
Related Questions
The dedendum circle diameter is equal to (where φ = Pressure angle)
Pitch circle diameter × cosφ
Addendum circle diameter × cosφ
Clearance circle diameter × cosφ
Pitch circle diameter × sinφ
When a close coiled helical spring is compressed, its wire is subjected to
Tension
Shear
Compression
All of the above
According to Indian standard specifications, 100 H6/g5 means that the
Basic size is 100 mm
Actual size is 100 mm
Difference between the actual size and basic size is 100 mm
None of the above
The piston rod of a steam engine is usually connected to the crosshead by means of
Bolted joint
Knuckle joint
Cotter joint
Universal joint
The speed of the sprocket reduces as the chain pitch __________ for a given number of teeth.
Increases
Decreases
Remain same
None of these
In most machine members, the damping capacity of the material should be
Low
Zero
High
Could be anything
A key capable of tilting in a recess milled out in a shaft is known as
Woodruff key
Feather key
Flat saddle key
Hollow saddle key
An open coiled helical compression spring 'A' of mean diameter 50 mm is subjected to an axial load W. Another spring 'B' of mean diameter 25 mm is similar to spring 'A' in all respects. The deflection of spring 'B' will be __________ as compared to spring 'A'.
One-eighth
One-fourth
One-half
Double
The velocity factor for precision metallic gears cut with high accuracy and operating at velocities upto 20 m/s is equal to
0.75/ (0.75 + √v)
3/ (3 + v)
4.5/ (4.5 + v)
6/ (6 + v)
The building up of worn and undersized parts, subjected to repeated loads by electroplating is
Best method
Extremely hazardous
Has no effect as regards fatigue strength
Cheapest method
According to Indian standard specifications, a grey cast iron designated by 'FG 200' means that the
Carbon content is 2%
Maximum compressive strength is 200 N/mm²
Minimum tensile strength is 200 N/mm²
Maximum shear strength is 200 N/mm²
Allen bolts are
Self locking bolts
Designed for shock load
Used in aircraft application
Provided with hexagonal depression in head
The difference between the tooth space and the tooth thickness as measured on the pitch circle, is called
Working depth
Clearance
Backlash
Face width
Crushing resistance required to crush the rivet per pitch length is
p.d.σc
p.t.σc
n.d.t.σc
(p - d) t.σc
When two helical springs of equal lengths are arranged to form a cluster spring, then
Shear stress in each spring will be equal
Load taken by each spring will be half the total load
Only A is correct
Both A and B is correct
A locking device in which the bottom cylindrical portion is recessed to receive the tip of the locking set screw, is called
Ring nut
Castle nut
Sawn nut
Jam nut
The rolling contact bearings as compared to sliding contact bearings have
Low starting and low running friction except at very high speeds
Accuracy of shaft alignment
Small overall dimensions
All of the above
The ratio of circumferential stress to longitudinal stress in a thin cylinder subjected to an internal pressure is
½
1
2
4
The stretching in a belt can be controlled by __________ the stress in the belt.
Reducing
Increasing
Both A and B
None of these
In a partial journal bearing, the angle of contact of the bearing with the journal is
120°
180°
270°
360°
In order to have a connecting rod equally strong in buckling about X-axis and Y-axis, the moment of inertia about X-axis should be __________ the moment of inertia about Y-axis.
Equal to
Twice
Three times
Four times
Two rigid plates are clamped by means of bolt and nut with an initial force F. After tightening, a separating force P (P < F) is applied to the lower plate, which in turn acts on the nut. The tension in the both after this is
F + P
F P
P
F
When the screw in a mechanical screw jack rotates, the load kept on the top of it moves
Axially upwards
Axially downwards
Axially upwards or downwards
None of these
A tube has the following advantage over pipe
Lighter and easier to handle
Greater shock absorption
Smoother inside walls
All of the above
In oilness bearings
The oil film pressure is generated only by the rotation of the journal
The oil film is maintained by supplying oil under pressure
Do not require external supply of lubricant
Grease required to be applied after some intervals
The objective of idler pulley in belt drive is to
Decrease the tendency of belt to slip
Increase the power transmission capacity
Increase the wrap angle and belt tension
All the above objectives
Which of the following statement is correct, for two shafts connected in parallel?
Torque in each shaft is the same
Shear stress in each shaft is the same
Angle of twist of each shaft is the same
Torsional stiffness of each shaft is the same
The connecting rod bolts are tightened up with initial tension greater than the external load so that
Joint may not open up
Bolts are weakest elements
The resultant load on the bolt would not be affected by the external cyclic load
Bolts will not loosen during service
A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, the junction radius is 60 mm and the junction pressure is 1.1 N/mm². The maximum hoop stress developed in the inner cylinder is
3.6 N/mm² compression
3.6 N/mm² tension
7.2 N/mm² compression
7.2 N/mm² tension
Which of the following formula is used in designing a connecting rod?
Euler's formula
Rankine's formula
Johnson's straight line formula
Johnson's parabolic formula