Which one of the following is a positive drive?
V-belt drive
Rope drive
Crossed flat belt drive
Chain drive
Correct Answer :
D. Chain drive
Related Questions
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
The material commonly used for machine tool bodies is
Mild steel
Aluminium
Brass
Cast iron
The connecting rod bolts are tightened up so that tightening stress
Is just sufficient to hold parts together
Approaches yield point
Is 50% of yield point
Is about yield point divided by safety factor
If P1 and P2 are the tight and slack side tensions in the belt, then the initial tension Pi (according to Barth) will be equal to
[(√P1 + √P2)/2]²
P1 + P2
2 × (P1 + P2)
[2 × (P1 + P2)] + Pc Where Pc is centrifugal tension
The edges of a boiler plate are bevelled to an angle of
30°
45°
60°
80°
Machine screws are
Similar to small size tap bolts except that a greater variety of shapes of heads are available
Slotted for a screw driver and generally used with a nut
Used to prevent relative motion between two parts
Similar to stud
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)
Which of the following statement is wrong for a connecting rod?
The connecting rod will be equally strong in buckling about X-axis and Y-axis, if Ixx = 4 Iyy
If Ixx > 4 Iyy, the buckling will occur about Y-axis
If Ixx < 4 Iyy, the buckling will occur about X-axis
The most suitable section for the connecting rod is T-section
The usual clearance provided in hydrodynamic bearing per mm of diameter of shaft is
0.01 micron
0.1 micron
1 micron
10 microns
The endurance limit in shear of carbon steel can be obtained by multiplying the endurance limit in flexure by a factor of
0.45
0.55
0.65
0.75
For a square key made of mild steel, the shear and crushing strength are related as
Shear strength is equal to crushing strength
Shear strength is greater than crushing strength
Shear strength is less than crushing strength
None of the above
The included angle for the V-belt is usually
10°-20°
30°-40°
40°-60°
60°-80°
According to Rankine's theory, the failure occurs at a point in a member
When the maximum shear stress in a biaxial stress system reaches the shear stress at elastic limit in a simple tension test
When the maximum principal stress in a biaxial stress system reaches the elastic limit of the material in a simple tension test
When the strain energy per unit volume in a biaxial stress system reaches the strain energy at the elastic limit per unit volume as determined from a simple tension test
When the maximum principal strain in a biaxial stress system reaches the strain at the elastic limit as determined from a simple tension test
Belt slip may occur due to
Heavy load
Loose belt
Driving pulley too small
All 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
Tensile strength of a mild steel specimen can be roughly predicted from following hardness test
Brinell
Rockwell
Vickers
None of the above
The objective of crowning of the flat pulleys of belt drive is to
Prevent the belt from running off the pulley
Increase the power transmission capacity
Increase the belt velocity
Prevent the belt joint from damaging the belt surface
The following type of nut is used with alien bolt
Hexagonal nut
Slotted nut
Castle nut
Any one of the above
A screw is said to be a self locking screw, if its efficiency is
Less than 50 %
More than 50 %
Equal to 50 %
None of these
In leaf springs, the longest leaf is known as
Master leaf
Lower leaf
Upper leaf
None of these
18/8 steel contains
18% nickel and 8% chromium
18% chromium and 8% nickel
18% nickel and 8% vanadium
18% vanadium and 8% nickel
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
A type of brake commonly used in motor cars is a
Shoe brake
Band and block brake
Band brake
Internal expanding brake
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
Jam 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 in 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 spitted and bent in reverse direction at other end
Idler pulley is used for
Increasing velocity ratio
For applying tension
Changing the direction of motion of belt
All of these
According to Indian standards, the diameter of rivet hole is made larger than the basic size of rivet by
0.5 mm upto rivet diameter of 24 mm
1 mm for rivet diameter from 27 mm to 36 mm
2 mm for rivet diameter from 39 mm to 48 mm
All of the above
In block brakes, the ratio of shoe width to wheel diameter is taken between
0.1 and 0.25
0.25 and 0.50
0.50 and 0.75
0.75 and 1
Allen bolts are
Self locking bolts
Designed for shock load
Used in aircraft application
Provided with hexagonal depression in head
The taper on cotter varies from
1 in 24 to 1 in 20
1 in 15 to 1 in 10
1 in 32 to 1 in 24
1 in 48 to 1 in 24