The groove angle of pulleys for V-belt is
340 to 360
420 to 450
More than 400
300 to 320
Correct Answer :
A. 340 to 360
Related Questions
Which process will increase the fatigue duration of parts?
Finishing and polishing
Shotpeening
De-carburisation
Electroplating
Fibrous fracture occurs in
Ductile material
Brittle material
Elastic material
Hard material
18/8 steel contains
18% nickel and 8% chromium
18% chromium and 8% nickel
18% nickel and 8% vanadium
18% vanadium and 8% nickel
A steel containing 0.8% carbon is known as
Eutectoid steel
Hypereutectoid steel
Hypo-eutectoid steel
None of these
In a flange coupling, the bolts are subjected to
Tensile stress
Compressive stress
Shear stress
None of these
If a load W is applied instantaneously on a bar; Then the stress induced in bar will
Be independent of ratio of mass of load W to mass of bar (y)
Increase with increase in y
Decrease with decrease in y
Depend on other considerations
When a circular beam of diameter d is subjected to a shear force F, the maximum shear stress induced will be
4F/ πd²
6F/ πd²
8F/ πd²
16F/ 3πd²
Taper usually provided on cotter is
1 in 5
1 in 10
1 in 24
1 in 40
The acme threads are usually found on
Spindles of bench vices
Railway carriage couplings
Feed mechanism of machine tools
Screw cutting lathes
Which of the following statement is correct?
The distance from a point on one thread to the corresponding point on the next thread is called pitch
The distance which a screw thread advances axially in one rotation of the nut is called lead
In single start threads, lead is equal to pitch
All of the above
Auto frettage is the method of
Joining thick cylinders
Calculating stresses in thick cylinders
Pre-stressing thick cylinders
Increasing the life of thick cylinders
Stress concentration in cyclic loading is more serious in
Ductile materials
Brittle materials
Equally serious in both cases
Depends on other factors
In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
The effect of curvature of the cylinder wall is neglected
The tensile stresses are uniformly distributed over the section of the walls
The effect of the restraining action of the heads at the end of the pressure vessel is neglected
All of the above
According to I.B.R., the efficiency of a triple riveted butt joint with double straps of unequal width (5 rivets per pitch length) should be
45 to 60 %
63 to 70 %
70 to 83 %
80 to 90 %
In the levers of first type, the mechanical advantage is __________ one.
Less than
Equal to
More than
None of these
For circumferential joint in boilers, the type of joint used is
Butt joint with single cover plate
Butt joint with double cover plate
Lap joint with one ring overlapping the other
Any one of the above
At low temperatures (say 75°C) the notched bar impact value of steel
Increases markedly
Decreases markedly
Remain same
Depends on heat treatment carried out
Ball bearing type screws are found in following application
Screw jack
Aeroplane engines
Crane
Steering mechanism
A fast and loose pulley drive is used when
Shafts are arranged parallel and rotate in the opposite directions
Shafts are arranged parallel and rotate in the same directions
Shafts are arranged at right angles and rotate in one definite direction
Driven shaft is to be started or stopped whenever desired without interfering with the driving shaft
A screw is said to be over hauling screw, if the
Friction angle is less than helix angle
Friction angle is more than helix angle
Friction angle is equal to helix angle
Efficiency of screw is 100%
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
The coefficient of friction between the belt and pulley depends upon the
Material of belt and pulley
Slip of belt
Speed of belt
All of these
In a steam engine, the piston rod is usually connected to the crosshead by means of a
Knuckle joint
Cotter joint
Oldham coupling
Universal joint
For a shaft diameter of 200 mm, the number of bolts in a marine flange coupling should be
8
6
4
10
The velocity factor for ordinary cut gears operating at velocities upto 12.5 m/s is equal to
0.75/ (0.75 + √v)
3/ (3 + v)
4.5/ (4.5 + v)
6/ (6 + v)
The contact ratio for gears is
Zero
Less than one
Greater than one
None of these
In an oil lubricated journal bearing, the coefficient of friction between the journal and the bearing
Remains constant at all speeds
Is minimum at zero speed and increases monotonically with increase in speed
Is maximum at zero speed and decreases monotonically with increase in speed
Becomes minimum at an optimum speed and then increases with further increase in speed
The piston pin bearings in heavy duty diesel engines are
Needle roller bearings
Tapered roller bearings
Spherical roller bearings
Cylindrical roller bearings
The cam follower extensively used in aircraft engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
The modulus of elasticity for mild steel is approximately equal to
80 kN/mm²
100 kN/mm²
110 kN/mm²
210 kN/mm²