18/8 steel contains
1.18% nickel and 8% chromium
2. 18% chromium and 8% nickel
3.18% nickel and 8% vanadium
4. 18% vanadium and 8% nickel
Posted Date:-2021-11-27 14:43:08
A bolt is designed on the basis of __________ with a large factor of safety.
1.Direct tensile stress
2.Direct compressive stress
3.Direct bending stress
4.Direct shear stress
Posted Date:-2021-11-27 14:26:26
A bolt of M 24 × 2 means that
1.The pitch of the thread is 24 mm and depth is 2 mm
2.Cross-sectional area of the threads is 24 mm²
3.The nominal diameter of bolt is 24 mm and pitch is 2 mm
4.The effective diameter of bolt is 24 mm and there are 2 threads per cm
Posted Date:-2021-11-27 15:27:25
A column of length l is fixed at both ends. The equivalent length of the column is
1.l/2
2. l/√2
3. l
4.2 l
Posted Date:-2021-11-27 15:06:48
A feather key is generally
1.Loose in shaft and tight in hub
2.Tight in shaft and loose in hub
3.Tight in both shaft and hub
4. Loose in both shaft and hub
Posted Date:-2021-11-27 14:31:02
A hollow saddle key is
1.A taper key which fits half in the key way of hub and half in the key way of shaft
2.A taper key which fits in a key way of the hub and is flat on the shaft
3.A taper key which fits in a key way of the hub and the bottom of the key is shaped to fit the curved surface of the shaft
4.Provided in pairs at right angles and each key is to withstand torsion in one direction only
Posted Date:-2021-11-27 15:33:50
A special case of ductility which permits materials to be rolled or hammered into thin sheets, is called
1.Plasticity
2.Elasticity
3.Ductility
4.Malleability
Posted Date:-2021-11-27 14:48:23
A tapered key which fits in a key way in the hub and the bottom of which is shaped to fit the curved surface of the shaft, is known as,
1.Hollow saddle key
2. Hollow key
3. Soft key
4.None of these
Posted Date:-2021-11-27 15:35:14
A type of brake commonly used in motor cars is a
1.Shoe brake
2.Band and block brake
3.Band brake
4.Internal expanding brake
Posted Date:-2021-11-27 15:10:47
For a bevel gear having the pitch angle θ, the ratio of formative number of teeth (TE) to actual number of teeth (T) is
1.1/sinθ
2.1/cosθ
3.1/tanθ
4.sinθ cosθ
Posted Date:-2021-11-27 14:38:31
For standard coarse threads of nut, the threads will be as strong in failure by shear as the bolt in tension, if the height of nut (h) is approximately
1.0.4 times
2.0.6 times
3.0.7 times
4.0.8 times
Posted Date:-2021-11-27 14:17:07
If a spring is cut down into two springs, the stiffness of cut springs will be
1.Half
2.Same
3.Double
4. None of the above
Posted Date:-2021-11-27 13:58:11
If the centre distance of the mating gears having involute teeth is varied within limits, the velocity ratio
1.Increases
2.Decreases
3.Remains unchanged
4.None of these
Posted Date:-2021-11-27 15:09:38
In designing a flange coupling, the pitch circle diameter of bolts is taken as (where d = Diameter of the shaft)
1. 2 d
2. 3 d
3. 4 d
4.5 d
Posted Date:-2021-11-27 15:05:15
In second type of levers,
1. Load is in between the fulcrum and effort
2.Effort is in between the fulcrum and load
3.Fulcrum is in between the load and effort
4.None of these
Posted Date:-2021-11-27 14:10:30
In the levers of third type, the mechanical advantage is __________ one.
1.Less than
2.Equal to
3.More than
4.None of these
Posted Date:-2021-11-27 15:18:33
In V-belt drive, belt touches
1.At bottom
2.At sides only
3.Both at bottom and sides
4.Could touch anywhere
Posted Date:-2021-11-27 14:11:53
Rankine Gordon formula for buckling is valid for
1. Long column
2.Short column
3. Short and long column
4.Very long column
Posted Date:-2021-11-27 15:15:02
Stress concentration is caused due to
1. Variations in load acting on a member
2.Variations in properties of materials in a member
3.Abrupt change of cross-section
4.All of these
Posted Date:-2021-11-27 14:09:19
The maximum efficiency of a square threaded screw is
1.(1 - sinφ)/ (1 + sinφ)
2.(1 + sinφ)/ (1 - sinφ)
3. (1 - sinφ)/ (1 + cosφ)
4. (1 + cosφ)/ (1 - sinφ)
Posted Date:-2021-11-27 15:20:06
The ratio of driving tensions for flat belts, neglecting centrifugal tension, is (where Tâ‚, and Tâ‚‚ = Tensions on the tight and slack sides of belt respectively, μ = Coefficient of friction, between the belt and pulley, and θ = Angle of contact)
1.Tâ‚/Tâ‚‚ = μθ
2. log (Tâ‚/Tâ‚‚) = μθ
3.Tâ‚/Tâ‚‚ =eμθ
4. Tâ‚/Tâ‚‚ = log μθ
Posted Date:-2021-11-27 14:21:33
The size of a cam depends upon
1.Base circle
2.Pitch circle
3.Prime circle
4.Pitch curve
Posted Date:-2021-11-27 15:29:17
When the screw in a mechanical screw jack rotates, the load kept on the top of it moves
1.Axially upwards
2. Axially downwards
3.Axially upwards or downwards
4.None of these
Posted Date:-2021-11-27 15:26:21
Which of the following property is essential for spring materials?
1.Stiffness
2.Ductility
3.Resilience
4.Plasticity
Posted Date:-2021-11-27 15:11:50
While designing a screw in a screw jack against buckling failure, the end conditions for the screw are taken as
1.Both the ends fixed
2.Both the ends hinged
3.One end fixed and the other end hinged
4.One end fixed and the other end free
Posted Date:-2021-11-27 14:27:23
. The distribution of the forces along the length of key fitted in a shaft
1. Varies linearly
2. Is uniform throughout
3.Varies exponentially, being more near the torque-input end
4.Varies exponentially, being less near the torque-input end
Posted Date:-2021-11-27 14:57:42
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
1. 3.6 N/mm² compression
2. 3.6 N/mm² tension
3. 7.2 N/mm² compression
4. 7.2 N/mm² tension
Posted Date:-2021-11-27 15:23:23
A double fillet welded joint with parallel fillet weld of length ‘l’ and leg ‘s’ is subjected to a tensile force ‘P’. Assuming uniform stress distribution, the shear stress in the weld is given by
1. √2P/s.l
2.P/2.s.l
3.P/√2.s.l
4. 2P/s.l
Posted Date:-2021-11-27 14:33:34
A key way lowers
1. The strength of the shaft
2.The rigidity of the shaft
3.Both the strength and rigidity of the shaft
4.The ductility of the shaft
Posted Date:-2021-11-27 14:36:18
According to I.B.R., the factor of safety of riveted joint should not be less than
1.1
2.2
3.3
4.4
Posted Date:-2021-11-27 15:30:27
According to I.B.R., when the thickness of the boiler shell (t) is less than 8 mm, then the diameter of the rivet hole (d) is obtained by
1.Equating tearing resistance of the plate to the shearing resistance of the rivets (B)
2.Equating tearing resistance of the plate to the crushing resistance of the rivets
3.Equating shearing resistance to the crushing resistance of the rivets
4.None of these
Posted Date:-2021-11-27 14:30:11
According to Indian standard specifications, 100 H6/g5 means that
1.Tolerance grade for the hole is 6 and for the shaft is 5
2. Tolerance grade for the shaft is 6 and for the hole is 5
3.Tolerance grade for the shaft is 4 to 8 and for the hole is 3 to 7
4.Tolerance grade for the hole is 4 to 8 and for the shaft is 3 to 7
Posted Date:-2021-11-27 14:58:38
According to Indian standard specifications, a Grey cast iron designated by 'FG 200' means that the (A)
1.Carbon content is 2%
2.Maximum compressive strength is 200 N/mm²
3.Minimum tensile strength is 200 N/mm²
4.Maximum shear strength is 200 N/mm²
Posted Date:-2021-11-27 14:24:28
Aircraft body is usually fabricated by
1.Welding
2.Pre-casting
3.Riveting
4.Casting
Posted Date:-2021-11-27 14:04:59
Allen bolts are
1. Self locking bolts
2.Designed for shock load
3.Used in aircraft application
4.Provided with hexagonal depression in head
Posted Date:-2021-11-27 14:19:07
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'.
1.One-eighth
2.One-fourth
3.One-half
4.Double
Posted Date:-2021-11-27 14:23:18
Belt slip may occur due to
1.Heavy load
2.Loose belt
3. Driving pulley too small
4. All of the above
Posted Date:-2021-11-27 14:01:14
If the centre distance of the mating gears having involute teeth is increased, then the pressure angle
1.Increases
2.Decreases
3.Remains unchanged
4.None of these
Posted Date:-2021-11-27 14:22:25
In a butt welded joint, the size of weld is __________ the throat of weld.
1. 0.5 times
2. Equal to
3.2 times
4.Double
Posted Date:-2021-11-27 14:28:13
In a gear, having Involute teeth, the normal to the Involute is a tangent to the
1.Base circle
2.Pitch circle
3.Addendum circle
4. Dedendum circle
Posted Date:-2021-11-27 14:18:10
In a marine flange coupling, the pitch circle diameter of bolts is taken as
1.1.2 d
2.1.6 d
3.2 d
4.2.5 d
Posted Date:-2021-11-27 14:52:53
In levers, leverage is the ratio of
1.Load lifted to the effort applied
2. Mechanical advantage to the velocity ratio
3.Load arm to the effort arm
4.Effort arm to the load arm
Posted Date:-2021-11-27 14:47:23
In oilness bearings
1.The oil film pressure is generated only by the rotation of the journal
2.The oil film is maintained by supplying oil under pressure
3. Do not require external supply of lubricant
4. Grease required to be applied after some intervals
Posted Date:-2021-11-27 14:07:47
In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
1.The effect of curvature of the cylinder wall is neglected
2.The tensile stresses are uniformly distributed over the section of the walls
3.The effect of the restraining action of the heads at the end of the pressure vessel is neglected
4.All of the above
Posted Date:-2021-11-27 15:43:39
Oldham coupling is used to connect two shafts
1. Which are perfectly aligned
2.Which are not in exact alignment
3.Which have lateral misalignment
4.Whose axes intersect at a small angle
Posted Date:-2021-11-27 15:28:22
The acme threads are usually found on
1.Spindles of bench vices
2.Railway carriage couplings
3.Feed mechanism of machine tools
4.Screw cutting lathes
Posted Date:-2021-11-27 14:32:48
The bending moment ‘M’ and a torque ‘T’ is applied on a solid circular shaft. If the maximum bending stress equals to maximum shear stress developed, then ‘M’ is equal to
1.T/2
2. T
3.2 T
4. 4 T
Posted Date:-2021-11-27 14:55:17
The bending stress in a curved beam is
1. Zero at the centroidal axis
2. Zero at the point other than centroidal axis
3.Maximum at the neutral axis
4.None of these
Posted Date:-2021-11-27 15:13:58
The circumferential and longitudinal strains in a cylindrical boiler under internal steam pressure are εc and εl respectively. The change in volume of the boiler cylinder per unit volume will be
1. εc + 2εl
2.2εc + εl
3. εc + εl²
4.εc² + εl
Posted Date:-2021-11-27 14:41:13
The coefficient of friction in belt drive depends upon
1.Material of belt
2.Material of pulley
3.Materials of belt and pulley
4.Belt velocity
Posted Date:-2021-11-27 14:03:13
The connecting rod bolts are tightened up so that tightening stress
1.Is just sufficient to hold parts together
2.Approaches yield point
3.Is 50% of yield point
4.Is about yield point divided by safety factor
Posted Date:-2021-11-27 14:40:22
The connecting rod bolts are tightened up with initial tension greater than the external load so that
1.Joint may not open up
2.Bolts are weakest elements
3.The resultant load on the bolt would not be affected by the external cyclic load
4.Bolts will not loosen during service
Posted Date:-2021-11-27 15:48:49
The cross-section of the arm of a bell crank lever is
1. Rectangular
2. Elliptical
3.I-section
4. Any one of these
Posted Date:-2021-11-27 15:46:42
The effective stress in wire ropes during normal working is equal to the stress due to
1. Axial load plus stress due to bending
2.Acceleration/retardation of masses plus stress due to bending
3. Axial load plus stress due to acceleration/retardation
4.Bending plus stress due to acceleration/retardation
Posted Date:-2021-11-27 14:45:59
The face of the tooth is the
1.Surface of the top of the tooth
2.Surface of the tooth above the pitch surface
3.Surface of the tooth below the pitch surface
4.Width of the tooth measured along the pitch circle
Posted Date:-2021-11-27 14:51:38
The form factor of a helical gear __________ with the increase in the helix angle.
1.Increases
2.Decreases
3.Remains constant
4.None of these
Posted Date:-2021-11-27 14:37:29
The helix angle for double helical gears may be made up to
1.45°
2.60°
3.75°
4. 90°
Posted Date:-2021-11-27 14:54:15
The included angle for the V-belt is usually
1.10°-20°
2.30°-40°
3.40°-60°
4.60°-80°
Posted Date:-2021-11-27 14:34:40
The material used for brake lining should have __________ coefficient of friction. (A) (B) (C)
1.Low
2.High
3.Moderate
4.None of these
Posted Date:-2021-11-27 14:42:03
The notch sensitivity q is expressed in terms of fatigue stress concentration factor Kf and theoretical stress concentration factor Kt as
1.(Kf + 1)/ (Kt + 1)
2. (Kf - 1)/ (Kt - 1)
3.(Kt + 1)/ (Kf + 1)
4.(Kt - 1)/ (Kf - 1)
Posted Date:-2021-11-27 15:08:18
The objective of caulking in a riveted joint is to make the joint
1. Free from corrosion
2.Stronger in tension
3. Free from stress
4. Leak-proof
Posted Date:-2021-11-27 15:12:43
The process which improves the machinability of steels, but lowers the hardness and tensile strength is
1. Normalising
2.Full annealing
3.Process annealing
4.Spheroidising
Posted Date:-2021-11-27 14:31:49
The radial distance of a tooth from the pitch circle to the top of the tooth is called
1.Addendum
2.Dedendum
3.Clearance
4.Working depth
Posted Date:-2021-11-27 14:13:10
The resistance to fatigue of a material is measured by
1.Elastic limit
2.Ultimate tensile strength
3.Young's modulus
4.Endurance limit
Posted Date:-2021-11-27 14:06:28
The resultant axial load on a bolt depends on
1. Initial tension
2.External load applied
3.Relative elastic yielding (springness) of the bolt and the connected member
4.All of the above
Posted Date:-2021-11-27 14:20:10
The width of the pulley should be __________ width of the belt.
1.Equal to
2. Less than
3.Greater than
4.None of these
Posted Date:-2021-11-27 14:35:25
Two closely coiled helical springs with stiffness kâ‚ and kâ‚‚ respectively are connected in series. The stiffness of an equivalent spring is given by
1.(kâ‚ kâ‚‚)/ (kâ‚ + kâ‚‚)
2. (kâ‚ - kâ‚‚)/ (kâ‚ + kâ‚‚)
3. (kâ‚ + kâ‚‚)/ (kâ‚ kâ‚‚)
4.(kâ‚ - kâ‚‚)/ (kâ‚ kâ‚‚)
Posted Date:-2021-11-27 15:44:46
Two shafts ‘A’ and ‘B’ under pure torsion are of identical length and identical weight and are made of the same material. The shaft ‘A’ is solid and the shaft ‘B’ is hollow. We can say that
1.Shaft B is better than shaft A
2. Shaft A is better than shaft B
3.Both the shafts are equally good
4.None of these
Posted Date:-2021-11-27 15:47:39
Wahl's stress factor __________ very rapidly as the spring index decreases.
1. Increases
2.Decreases
3.Remain same
4.None of these
Posted Date:-2021-11-27 14:49:33
When a material is subjected to fatigue loading, the ratio of the endurance limit to the ultimate tensile strength is
1.0.20
2.0.35
3.0.50
4.0.65
Posted Date:-2021-11-27 15:32:07
When an open coiled helical compression spring is subjected to an axial compressive load, the maximum shear stress induced in the wire is (where D = Mean diameter of the spring coil, d = Diameter of the spring wire, K = Wahl's stress factor, and W = Axial compressive load on the spring)
1.(WD/ πd3) × K
2. (2WD/ πd3) × K
3. (4WD/ πd3) × K
4.(8WD/ πd3) × K
Posted Date:-2021-11-27 14:50:44
When carbon in the cast iron is principally in the form of graphite, the cast iron will be of
1.Brown colour
2.Yellow colour
3.White colour
4. Grey colour
Posted Date:-2021-11-27 13:59:06
When the length of the journal is equal to the diameter of the journal, then the bearing is said to be a
1. Short bearing
2.Long bearing
3.Medium bearing
4.Square bearing
Posted Date:-2021-11-27 15:36:55
Which of the following has threads at both ends?
1. Bolt
2.Tap bolt
3.Stud
4.None of these
Posted Date:-2021-11-27 14:39:13
Which of the following spring is used in mechanical wrist watch?
1. Helical compression spring
2.Spiral spring
3.Torsion spring
4.Belleville spring
Posted Date:-2021-11-27 14:44:33