The acme threads are usually found on
Spindles of bench vices
Railway carriage couplings
Feed mechanism of machine tools
Screw cutting lathes
Correct Answer :
D. Screw cutting lathes
Related Questions
Screws used for power transmission should have
Very fine threads
High efficiency
Low efficiency
Strong teeth
Which one of the following is a positive drive?
V-belt drive
Rope drive
Crossed flat belt drive
Chain drive
When the belt is transmitting maximum power,
The tension in tight side is twice the centrifugal tension
The tension in slack side is equal to the centrifugal tension
The tension in tight side is thrice the centrifugal tension
None of the above
Plastic flow in ductile materials
Increases the seriousness of static loading stress concentration
Lessens the seriousness of static loading stress concentration
Has no effect on it
Depends on other considerations
Rankine's theory is used for
Brittle materials
Ductile materials
Elastic materials
Plastic materials
Endurance limit or fatigue limit is the maximum stress that a member can withstand for an infinite number of load applications without failure when subjected to
Dynamic loading
Static loading
Combined static and dynamic loading
Completely reversed loading
The taper on key is given on
Bottom side only
Top side only
On both sides
Any side
A single strap butt joint is always in __________ shear.
Single
Double
Triple share
None of these
The arms of the pulleys for flat belt drive have
Elliptical cross-section
Major axis in plane of rotation
Major axis twice the minor axis
All the three characteristics
Castle nut is a locking device in which
One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly is middle of nut and then slot reduced by tightening a screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end
For same pulley diameters, center distance, belt speed and belt and pulley materials,
Open belt drive transmits more power than crossed belt drive
Crossed belt drive transmits more power than open belt drive
Open and crossed belt drives transmit same power
Power transmission does not depend upon open and crossed types of constructions
The bending stress in a curved beam is
Zero at the centroidal axis
Zero at the point other than centroidal axis
Maximum at the neutral axis
None of these
The helix angle for single helical gears ranges from
10° to 15°
15° to 20°
20° to 35°
35° to 50°
Stress concentration is caused due to
Variations in load acting on a member
Variations in properties of materials in a member
Abrupt change of cross-section
All of these
When two non-parallel or intersecting but coplanar shafts are connected by gears, the arrangement is known as,
Bevel gearing
Helical gearing
Worm gearing
None of these
In replacing the V-belts, a complete set of new belts is used instead of replacing a single damaged belt because
Belts are available in sets
Only one belt cannot be fitted with other used belts
The new belt will carry more than its share and result in short life
New and old belts will cause vibrations
Which of the following has threads at both ends?
Bolt
Tap bolt
Stud
None of these
The strength of a riveted joint is equal to
Tearing strength of plate (Pt)
Shearing strength of rivet (Ps)
Crushing strength of rivet (Pc)
Least value of Pt Ps and Pc
Which of the following statement is wrong?
The pitch of rivets is obtained by equating the tearing resistance of the plate to the shearing resistance of the rivets
The pitch of rivets should not be less than 2d, where d is the diameter of rivet hole
The maximum value of the pitch of rivets for a longitudinal joint of a boiler, as per I.B.R., is given by Pmax = C.t + 41.28 mm
According to I.B.R., the thickness of butt strap shall not be less than 5 mm
Ball bearing type screws are found in following application
Screw jack
Aeroplane engines
Crane
Steering mechanism
In skew bevel gearing, the axes of shafts are
Intersecting and the teeth are curved
Non-intersecting and nonparallel and the teeth are curved
Non-intersecting and non-parallel and the teeth are straight
None of the above
The designation M 33 × 2 of a bolt means
Metric threads of 33 numbers in 2 cm
Metric threads with cross-section of 33 mm
Metric threads of 33 mm outside diameter and 2 mm pitch
Bolt of 33 mm nominal diameter having 2 threads per cm
In thrust bearings, the load acts
Along the axis of rotation
Parallel to the axis of rotation
Perpendicular to the axis of rotation
In any direction
Stress concentration in static loading is more serious in
Ductile materials
Brittle materials
Equally serious in both cases
Depends on other factors
A spring of stiffness 1000 N/m is stretched initially by 100 mm from the undeformed position. The work required to stretch it by another 100 mm is
5 N-m
7 N-m
10 N-m
15 N-m
Two shafts of the same length and material are joined in series. If the ratio of their diameters is 2, then the ratio of their angles of twist will be
2
4
8
16
Rankine Gordon formula for buckling is valid for
Long column
Short column
Short and long column
Very long column
In Vickers hardness testing, the pyramid indentor apex is
40°
122°
136°
152°
The contact ratio for gears is
Zero
Less than one
Greater than one
None of these
In a partial journal bearing, the angle of contact of the bearing with the journal is
120°
180°
270°
360°