This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Springs”.
- Which of the following function can the spring perform?
a) Store energy
b) Absorb shock
c) Measure force
d) All of the mentioned - The helix angle is very small about 2⁰. The spring is open coiled spring.
a) Yes
b) It is closed coiled spring
c) That small angle isn’t possible
d) None of the listed - The helical spring ad wire of helical torsion spring, both are subjected to torsional shear stresses.
a) True
b) False - The longest leaf in a leaf spring is called centre leaf.
a) It is called middle leaf
b) It is called master leaf
c) Yes
d) None of the listed - Multi leaf springs are not recommended for automobile and rail road suspensions.
a) True
b) False - The spring index is the ratio of wire diameter to mean coil diameter.
a) True
b) False - If spring index=2.5, what can be concluded about stresses in the wire?
a) They are high
b) They are negligible
c) They are moderate
d) Cannot be determined - A spring with index=15 is prone to buckling.
a) True
b) False - If the spring is compressed completely and the adjacent coils touch each other,the the length of spring is called as?
a) Solid length
b) Compressed length
c) Free length
d) None of the mentioned - If number of coils are 8 and wire diameter of spring 3mm, then solid length is given by?
a) None of the listed
b) 27mm
c) 24mm
d) 21mm - Compressed length is smaller than the solid length.
a) True
b) False - Pitch of coil is defined as axial distance in compressed state of the coil.
a) Yes
b) It is measured in uncompressed state
c) It is same in uncompressed or compressed state
d) None of the listed - If uncompressed length of spring is 40mm and number of coils 10mm, then pitch of coil is?
a) 4
b) 40/9
c) 40/11
d) None of the mentioned - Active and inactive, both types of coils support the load although both don’t participate in spring action.
a) Active coils don’t support the load
b) Inactive coils don’t support the load
c) Both active and inactive don’t support the load
d) Both active and inactive support the load
This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Modes of Failure & Different kind of Stresses”.
- A mechanical component may fail as a result of which of the following
a) elastic deflection
b) general yielding
c) fracture
d) each of the mentioned - Type of load affects factor of safety.
a) True
b) False - For cast iron components, which of the following strength are considered to be the failure criterion?
a) Ultimate tensile strength
b) Yield Strength
c) Endurance limit
d) None of the mentioned - For components made of ductile materials like steel, subjected to static loading which of the following strength is used as a failure of criterion?
a) Yield strength
b) Ultimate strength
c) Endurance limit
d) None of the mentioned - Pitting occurs on _ of the component.
a) Surface
b) Inner body
c) Inside or on surface - Buckling is elastic instability which leads to sudden large lateral deflection.
a) True
b) False - The critical buckling load depends upon which of the following parameters?
a) Yield strength
b) Modulus of elasticity
c) Radius of gyration
d) Each of the mentioned - If there are residual stresses in the material, than lower factor of safety is used.
a) True
b) False - Which of the following relationship is true? (p=Poisson’s ratio)
a) E=2G (1+p)
b) E=G (2+p)
c) E= 2(G+ p)
d) No relation exist between E, G and p - Modulus of rigidity for carbon steels is greater than that of grey cast iron.
a) True
b) False - According to principal stress theory, which option represents the correct relation between yield strength in shear (YSS) and the yield strength in tension (YST)?
a) YSS=0.5YST
b) YSS=0.577YST
c) YST=0.5YSS
d) YST=0.577YSS
12 .A beam subjected to bending moment undergoes which of the following stresses?
a) Compressive
b) Tensile
c) Both compressive & tensile
d) None of the mentioned
- The bending stress varies _ with the distance from the neutral axis.
a) Linearly
b) Inversely
c) Squarely
d) Bending stress is independent of distance from the neutral axis
This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Stress Concentration & Its Factors”.
- Stress concentration is defined as the localization of high stresses due to irregularities present in the component and no changes of the cross section.
a) True
b) False - Stress Concentration Factor is the ratio of nominal stress obtained by elementary equations for minimum cross-section and highest value of actual stress near discontinuity.
a) True
b) False - If a flat plate with a circular hole is subjected to tensile force, then its theoretical stress concentration factor is?
a) 2
b) 3
c) 4
d) 1 - For an elliptical hole on a flat plate, if width of the hole in direction of the load decrease, Stress Concentration Factor will______
a) Increase
b) Decrease
c) Remains constant
d) Can’t be determined. Varies from material to material - In which of the following case stress concentration factor is ignored?
a) Ductile material under static load
b) Ductile material under fluctuating load
c) Brittle material under static load
d) Brittle material under fluctuating load - Is it logical to use fluid analogy to understand the phenomenon of stress concentration?
a) True
b) False - Use of multiple notches in a V shaped flat plate will
a) Reduce the stress concentration
b) Increase the stress concentration
c) No effect
d) Cannot be determined - Which of the following reduces the stress concentration?
a) Use of multiple notches
b) Drilling additional holes
c) Removal of undesired material
d) Each of the mentioned - A flat plate 30mm wide and “t”mm wide is subjected to a tensile force of 5kN. The plate has a circular hole of diameter 15mm with the centre coinciding with the diagonal intersection point of the rectangle. If stress concentration factor=2.16, find the thickness of the plate if maximum allowable tensile stress is 80N/mm².
a) 8mm
b) 9mm
c) 10mm
d) 12mm
This set of Machine Design quiz focuses on “Unsymmetrically Loaded Welded Joints”.
Answer the question 1-7 with respect to figure 1
- The two welds shown in the figure experience equal resisting force?
a) True
b) False - The moment of forces about the CG is ?
a) Zero
b) Infinite
c) P₁y₁+P₂y₂
d) None of the listed - Which equations can be used to find the resisting force in the two welds?
a) P=P₁+P₂
b) P₁+P₂=0
c) Both P=P₁+P₂ and P₁y₁=P₂y₂
d) P₁y₁=P₂y₂ - For the following welded joint l₁y₁=l₂y₂.
a) True
b) False - Find the total length of weld required to with stand the load of 100kN. Permissible shear stress in weld is 70kN/mm².
a) None of the listed
b) 101.03mm
c) 202.06mm
d) 30309mm
Answer: c
Explanation: 100000=0.707x10xlx70.
- Find the length of weld 2 required to with stand the load of 100kN. Permissible shear stress in weld is 70kN/mm².
a) None of the listed
b) 102.22mm
c) 132.4mm
d) 70.16mm - Find the length of weld 1 required to with stand the load of 100kN. Permissible shear stress in weld is 70kN/mm².
a) None of the listed
b) 102.22mm
c) 132.4mm
d) 70.16mm
Figure 2
Answer the following questions with respect to figure 2
- The following welded joint is an example of
a) Eccentric Load in plane of welds
b) Axial load in plane of welds
c) Axial load in plane perpendicular to plane of welds
d) None of the mentioned - What kind of stresses does the welded joint undergo?
a) Torsional shear stress
b) Direct shear stress
c) Direct and torsional shear stress
d) None of the listed - While considering moment of inertia for calculating torsional shear stress, J=I(xx) + I(yy), which of the following can be neglected in context with the following figure?
a) I(xx)
b) I(yy)
c) Both I(xx) and I(yy)
d) None of the listed - Calculate the direct shear stress in the welds by ignoring torsional shear stress if P=8kN and thickness of weld is 5mm.
a) None of the listed
b) 12.33N/mm
c) 13.33N/mm
d) 14.33N/mm - Determine the torsional shear stress in the welds if P=8kN and thickness of the welds is assumed t.
a) None of the listed
b) 456.34/t
c) 543.13/t
d) 589.31/t - Find the thickness of the weld if P=8kN and permissible shear stress in the welds is 100N/mm²
a) 4mm
b) 5mm
c) 6mm
d) 7mm
This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on “Eccentrically Loaded Riveted Joints”.
Figure 1
Answer the following questions in context to figure 1.
- A bracket is attached to a vertical wall by means of four rivets. Find the rivet which is under maximum stress.
a) 1 and 4
b) 2 and 3
c) 3 and 1
d) 4 and 2 - Calculate the primary shear stress on each rivet if P=30kN and diameter of rivets is 15mm.
a) None of the listed
b) 21.2 N/mm²
c) 42.4N/mm²
d) 169.6 N/mm² - If secondary shear stress acting on any bolts is given by Cxr₁ where r₁ is the distance of bolt from CG, then find the value of C. Bolts are equidistant with spacing of 100mm. Force P=30kN.
a) 46
b) 50
c) 72
d) 64 - Calculate the effective force in vector form to which rivet 2 is subjected. Bolts are separated by 100mm and force P=30kN.
a) 7500j+3600i
b) 7500j-3600i
c) -7500j-3600i
d) None of the listed - Calculate the effective force in vector form to which rivet 4 is subjected. Bolts are separated by 100mm and force P=30kN.
a) 7500j+7200i
b) None of the listed
c) 7500j+7200i
d) 7500j+7200i - Calculate the diameter of the rivets if permissible shear stress is 60N/mm². Bolts are separated by 100mm and force P=30kN.
a) 10mm
b) 12mm
c) 13mm
d) 15mm - Are the bolts 2 and 3 under same force?
a) Yes
b) No
c) Depends on nature of force whether it is of shear or bending in nature
d) Can’t be determined - Are the bolts 2 and 3 subjected to same magnitude of force?
a) True
b) False - Can we use the rivets of diameter 18mm in the following case if P=30kN and bolts are separated by 100mm each. Maximum permissible shear stress is 60N/mm².
a) Always
b) Never
c) In some cases
d) Cannot be determined - While designing shaft on the basis of torsional rigidity, angle of twist is given by?
a) Ml/Gd⁴
b) 584Ml/Gd⁴
c) 292 Ml/Gd⁴
d) None of the mentioned - According to ASME code, maximum allowable shear stress is taken as X% of yield strength or Y% of ultimate strength.
a) X=30 Y=18
b) X=30 Y=30
c) X=18 Y=18
d) X=18 Y=30 - Does ASME Standard take into consideration shock and fatigue factors?
a) Yes
b) No
Figure 1
The layout of a shaft supported on bearings at A & B is shown. Power is supplied by means of a vertical belt on pulley B which is then transmitted to pulley C carrying a horizontal belt. The angle of wrap is 180’ and coefficient of friction is 0.3. Maximum permissible tension in the rope is 3kN. The radius of pulley at B & C is 300mm and 150mm.
For questions 4-7, refer to figure 1.
- Calculate the torque supplied to the shaft.
a) 453.5N-m
b) 549.3N-m
c) 657.3N-m
d) None of the listed - Calculate the tension in the rope of pulley C.
a) 6778.3N and 7765.3N
b) 5948.15N and 2288.75N
c) 5468.4N ad 8678.3N
d) None of the listed - If allowable shear stress in the shaft is 70N/mm² and torsional and bending moments are M=1185000N-mm and m=330000N-mm, find the diameter of the shaft.
a) 36.8mm
b) 39.7mm
c) 44.7mm
d) 40.3mm - If bending moment on point B in horizontal plate is M and in vertical plane is m, then the net bending moment at point B is?
a) M
b) m
c) M+m
d) √M²+m² - Calculate the shaft diameter on rigidity basis if torsional moment is 196000N-mm, length of shaft is 1000mm. Permissible angle of twist per meter is 0.5’ and take G=79300N/mm².
a) None of the listed
b) 41.2mm
c) 35.8mm
d) 38.8mm - If yielding strength=400N/mm², the find the permissible shear stress according to ASME standards.
a) 72 N/mm²
b) 76 N/mm²
c) 268 N/mm²
d) 422 N/mm² - The stiffness of solid shaft is more than the stiffness of hollow shaft with same weight.
a) True
b) False - The strength of hollow shaft is more than the strength of solid shaft of same weight.
a) True
b) False - Solid shaft is costlier than hollow shaft of same weight.
a) True
b) False - Solid shafts are used in epicyclic gearboxes.
a) True
b) False - Flexible shafts have _ rigidity in torsion making them flexible.
a) Low
b) High
c) Very high
d) Infinitely small - Flexible shafts have __ rigidity in bending moment.
a) High
b) Low
c) Very high
d) Extremely low - A force 2P is acting on the double transverse fillet weld. Leg of weld is h and length l. Determine the shear stress in a plane inclined at θ with horizontal.
a) PSinθ(Sinθ+Cosθ)/hl
b) P(Sinθ+Cosθ)/hl
c) Pcosθ(Sinθ+Cosθ)/hl
d) None of the listed - Maximum shear stress in transverse fillet weld of leg h and length l is
a) P/hl
b) 1.21P/hl
c) P/1.21hl
d) None of the listed - A sunk key fits in the keyway of the _ only.
a) Hub
b) Sleeve
c) Both hub and sleeve
d) Neither hub nor sleeve - Hollow saddle key is superior to flat saddle key as far as power transmitting capability is concerned.
a) True
b) False - Saddle key is more suitable than sunk key for heavy duty applications.
a) True
b) False - The main advantage of sunk key is that it is a _ drive.
a) Positive
b) Negative
c) Neutral
d) None of the listed - Woodruff key permits _ movement b/w shaft and the hub.
a) Axial
b) Radial
c) Eccentric
d) None of the listed - Determine the length of kennedy key required to transmit 1200N-m and allowable shear in the key is 40N/mm². The diameter of shaft and width of key can be taken as 40mm and 10mm respectively.
a) 49mm
b) 36mm
c) 46mm
d) 53mm - Splines are keys.
a) True
b) False - Involute splines have stub teeth with a pressure angle of _
a) 30
b) 45
c) 60
d) Can’t be determined - Piston rod is an example of column.
a) True
b) False - Bucking of column means
a) Lateral deflection
b) Axial deflection
c) Torsional deflection
d) None of the listed - Slenderness ratio is [l= length of column and k= least radius of gyration of cross section about its axis].
a) l/k
b) k/l
c) l/2k
d) k/2l - Columns with what slenderness ratio are not designed with respect to buckling but are designed for compressive stresses.
a) >1
b) <1 c) >30
d) <30 - If slenderness ratio=45, which mode of failure will dominate?
a) Buckling
b) Compressive Stresses
c) Both buckling and compressive stress
d) Can’t be stated - Short column and long column are classified on the basis of
a) Slenderness ratio
b) Diameter
c) Length
d) None of the listed - Cast iron column with a slenderness ratio of 75 are
a) Short Columns
b) Long Columns
c) Very short columns
d) None of the listed - Steel columns with a slenderness ratio of 95 are
a) Short Columns
b) Long columns
c) Very long columns
d) None of the listed - Which of the following are true for End fixity coefficient
a) Dimensionless number
b) Used in Euler’s equation
c) Provides condition of restraint at two ends
d) All of the listed - Value of end fixity coefficient for both hands fixed is
a) 1
b) 4
c) 2
d) 0.25 - The normal stress is perpendicular to the area under considerations, while the shear stress acts over the area.
a) True
b) False - If a body is subjected to stresses in xy plane with stresses of 60N/mm² and 80N/mm² acting along x and y axes respectively. Also the shear stress acting is 20N/mm²Find the maximum amount of shear stress to which the body is subjected.
a) 22.4mm
b) 25mm
c) 26.3mm
d) 27.2mm - If a body is subjected to stresses in xy plane with stresses of 60N/mm² and 80N/mm² acting along x and y axes respectively. Also the shear stress acting is 10N/mm². Find the inclination of the plane in which shear stress is maximal.
a) 45’
b) 30’
c) 60’
d) 15’ - If a body is subjected to stresses in xy plane with stresses of 60N/mm² and 80N/mm² acting along x and y axes respectively. Also the shear stress acting is 20N/mm². Find the maximum normal stress.
a) 90
b) 92.4
c) 94.2
d) 96 - If a body is subjected to stresses in xy plane with stresses of 60N/mm² and 80N/mm² acting along x and y axes respectively. Also the shear stress acting is 20N/mm². Find the minimum normal stress.
a) 45.4
b) 47.6
c) 48.2
d) 50.6 - If compressive yield stress and tensile yield stress are equivalent, then region of safety from maximum principal stress theory is of which shape?
a) Rectangle
b) Square
c) Circle
d) Ellipse - Maximum Principal Stress Theory is not good for brittle materials.
a) True
b) False - The region of safety in maximum shear stress theory contains which of the given shape
a) Hexagon
b) Rectangle
c) Square
d) None of the mentioned - The total strain energy for a unit cube subjected to three principal stresses is given by?
a) U= [(σέ) ₁ + (σέ) ₂+ (σέ) ₃]/3
b) U= [(σ₁²+σ₂²+σ₃²)/2E] – (σ₁σ₂+σ₂σ₃+σ₃σ₁)2μ
c) U= [(σέ) ₁ + (σέ) ₂+ (σέ) ₃]/4
d) None of the mentioned - Distortion energy theory is slightly liberal as compared to maximum shear stress theory.
a) True
b) False
This set of Engineering Drawing Multiple Choice Questions & Answers (MCQs) focuses on “Riveted Joints”. - What type of failure will occur when rivets are smaller than necessary?
a) Tearing of plate between the holes
b) Tearing of plate between the edges
c) Shearing of rivet
d) Crushing of plate
View Answer
Answer: c
Explanation: Shearing of the rivet takes place if the diameter of the rivet is smaller than necessary. Tearing of the plate between the edges of the plate and rivet-hole takes place if the hole is too near the edge. - The necessary diameter (d) for thickness of plates (t) is __
a) d = 6√t b) d =4√t
c) d =6√2t d) d =4√2t
View Answer
Answer: a
Explanation: To prevent failure, the joint should be carefully designed. For elementary work, suitable values of the rivet diameter, positions of holes etc. for a given thickness of the plates the given empirical formulae is used. - The thickness of the fullering tool is about the _ as that of the plates.
a) double
b) same
c) half
d) one third
View Answer
Answer: b
Explanation: To prevent leakage through the joint, the plates are firmly formed together by caulking or fullering processes. Both the processes are generally performed with the aid of pneumatic power. The thickness of the fullering tool is about the same as that of the plates. - Tearing of the plate between the holes is taken when ____________
a) they are near to each other
b) the hole is too near the edge
c) diameter of rivet is too small
d) rivet and plate is of different metals
View Answer
Answer: a
Explanation: Tearing of the plate between the holes takes place if they are very near to each other. Tearing of the plate between the edges of the plate and rivet-hole takes place if the hole is too near the edge. - Tearing of the plate between the edges of the plate and rivet-hole takes place when __
a) they are near to each other
b) the hole is too near the edge
c) diameter of rivet is too small
d) rivet and plate is of different metals
View Answer
Answer: b
Explanation: Tearing of the plate between the edges of the plate and rivet-hole takes place if the hole is too near the edge. Tearing of the plate between the holes takes place if they are very near to each other. - In a lap joint, if the plates are connected to each other when the joint is made with only one row of rivets then it is called double-riveted lap joint.
a) True
b) False
View Answer
Answer: b
Explanation: For a lap joint, if the plates are made to connect using only one row of rivets then it is called single-riveted lap joint. A joint is said to be double-riveted, triple riveted etc. accordingly to the number of rows of rivets in it. - A joint is said to be double-riveted, triple riveted etc. accordingly to the number of sheets used.
a) True
b) False
View Answer
Answer: b
Explanation: For a lap joint, if the plates are made to connect using only one row of rivets then it is called single-riveted lap joint. A joint is said to be double-riveted, triple riveted etc. accordingly to the number of rows of rivets in it. - Width (L) of overlap of sheets is equal to __ when d is the diameter of a rivet in case of single-riveted lap joint.
a) 2d
b) 3d
c) 4d
d) 5d
View Answer
Answer: b
Explanation: For a lap joint, if the plates are made to connect using only one row of rivets then it is called single-riveted lap joint. The width of overlap L is equal to 3d when d is the diameter of rivet. - In zigzag lap joint formation when P is the pitch between the rivets, the distance between the rows of rivets should not be less than _
a) 0.6P
b) 0.8P
c) P
d) 1.2P
View Answer
Answer: a
Explanation: When two or more rows of rivets are required, rivets may be arranged in chain or zigzag formations. In chain formation the rivets are arranged directly opposite to each other but in zigzag they are staggered. - In butt joint when one strap is used the thickness varies between to _ (T is the thickness of plate to be connected).
a) T, 1.125T
b) 0.7T, 0.8T
c) 0.5T, T
d) T, 1.5T
View Answer
Answer: a
Explanation: In a butt joint, edges of the plates to be connected are butted against each other and the joint between them is covered by butt-plates or butt-straps on one or both sides. At least two rows of rivets, one in each connected plate, are necessary to make the joint. - In butt joint when two straps are used the thickness varies between to _ (T is the thickness of plate to be connected).
a) T, 1.125T
b) 0.7T, 0.8T
c) 0.5T, T
d) T, 1.5T
View Answer
Answer: b
Explanation: In a butt joint, edges of the plates to be connected are butted against each other and the joint between them is covered by butt-plates or butt-straps on one or both sides. At least two rows of rivets, one in each connected plate, are necessary to make the joint. - The flat ends of a boiler are prevented from bulging out and are strengthened by means of _
a) connection of plates at right angles
b) gusset stays
c) welding
d) riveting
View Answer
Answer: b
Explanation: Gusset stay is a plate which connects the flat end and the cylindrical shell of a boiler. Lengths of angle-section are used to make the joints. The flat ends of a boiler are prevented from bulging out and are strengthened by means of these stays.
