140 + Mcqs in Design of Machine Elements McqOptions

1.	A knuckle joint can be used in valve mechanism of a reciprocating engine.
A.	yes
B.	no
C.	yes but there are stress probles
D.	no as it is very dangerous to use
Answer» B. no

Discussion

2.	The strength of hollow shaft is more than the strength of solid shaft of same weight.
A.	true
B.	false
Answer» B. false

Discussion

3.	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
Answer» D. 40.3mm

Discussion

4.	Which of the following increases the dry strength of the sand?
A.	iron oxides
B.	fuel oils
C.	cereals
D.	dextrin and molasses
Answer» E.

Discussion

5.	Modulus of resilience is defined as
A.	strain energy per unit volume
B.	strain energy per unit area
C.	independent of strain energy
D.	none of the mentioned
Answer» B. strain energy per unit area

Discussion

6.	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
Answer» C. 35.8mm

Discussion

7.	Cylindrical load bearing has lower load capacity as compared to deep groove ball bearing.
A.	true
B.	false
Answer» C.

Discussion

8.	If a clearance fit is present between shaft and hole, what is the tolerance on shaft or hole for a complete interchangeable approach?
A.	½ of maximum clearance – ½ of minimum clearance
B.	¼ of maximum clearance – ¼ of minimum clearance
C.	maximum clearance – minimum clearance
D.	¾ of maximum clearance – ¾ of minimum clearance
Answer» B. ¼ of maximum clearance – ¼ of minimum clearance

Discussion

9.	When two hyperboloids are rotated, the resulting motion is
A.	sliding
B.	turning
C.	combination of turning and sliding
D.	rotary
Answer» D. rotary

Discussion

10.	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
Answer» C. both active and inactive don’t support the load

Discussion

11.	When the pitch angle is greater than 90⁰, it is called external bevel gear.
A.	true
B.	internal
C.	helical
D.	herringbone
Answer» C. helical

Discussion

12.	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
Answer» B. p(sinθ+cosθ)/hl

Discussion

13.	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
Answer» E.

Discussion

14.	Quality checking of riveted joint is much expensive than that of welded joint.
A.	true
B.	false
Answer» C.

Discussion

15.	Compressed length is smaller than the solid length.
A.	true
B.	false
Answer» C.

Discussion

16.	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
Answer» D. 21mm

Discussion

17.	There is problem of alignment in deep groove ball bearings.
A.	yes
B.	no, it is self-aligning
C.	it aligns itself only in some particular cases
D.	can’t be determined
Answer» B. no, it is self-aligning

Discussion

18.	Crown gears having a pitch angle of 90⁰
A.	0
B.	<90
C.	>90
D.	none of the listed
Answer» D. none of the listed

Discussion

19.	The stiffness of solid shaft is more than the stiffness of hollow shaft with same weight.
A.	true
B.	false
Answer» C.

Discussion

20.	The ratio of the maximum fluctuation of energy to the ……. is called coefficient of fluctuation of energy.
A.	minimum fluctuation of energy
B.	workdone per cycle
C.	maximum fluctuation of energy
D.	none of the mentioned
Answer» C. maximum fluctuation of energy

Discussion

21.	Which of the following are characteristics of skew bevel gears?
A.	straight teeth
B.	mounted on parallel shafts
C.	mounted on intersecting shafts
D.	all of the mentioned
Answer» B. mounted on parallel shafts

Discussion

22.	1816/ [7200 x 10.8184 x 50] or σ=100.6N/mm².
A.	14.80mm
B.	13.95mm
C.	16.5mm
D.	17.2mm
Answer» C. 16.5mm

Discussion

23.	In manual assembly, cost of screw is higher than the cost of driving a screw.
A.	true
B.	false
Answer» C.

Discussion

24.	What is the amount of sea coal needed in cast irons for large green casting moulding sands?
A.	10%
B.	15%
C.	20%
D.	25%
Answer» B. 15%

Discussion

25.	The main advantage of sunk key is that it is a drive.
A.	positive
B.	negative
C.	neutral
D.	none of the listed
Answer» B. negative

Discussion

26.	1816mm and radius of centroidal axis is 100mm, then find the bending stress at inner fibre whose radius is 50mm. Area of cross section of beam is 7200mm² and the beam is loaded with 100kN of load.
A.	97.3
B.	95.8
C.	100.6
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

27.	The safe stress for a hollow steel column which carries an axial load of 2100 kN is 125 MN/m2. if the external diameter of the column is 30cm, what will be the internal diameter?
A.	25 cm
B.	26.19cm c) 30.14 cm
C.	27.9 cm
Answer» C. 27.9 cm

Discussion

28.	A spring with index=15 is prone to buckling.
A.	true
B.	false
Answer» B. false

Discussion

29.	Maximum carbon content in welding is usually limited to
A.	0.22%
B.	0.8%
C.	1.5%
D.	2%
Answer» B. 0.8%

Discussion

30.	67 N/mm².; Spigot dia=65mm; thickness 0f collar=15mm
A.	131mm
B.	139mm
C.	141mm
D.	149mm
Answer» B. 139mm

Discussion

31.	Calculate the diameter of pin from shear consideration with maximum shear stress allowed is 40NN/mm² and an axial tensile force of 50kN is acting on the rod.
A.	39mm
B.	44mm
C.	49mm
D.	52mm
Answer» B. 44mm

Discussion

32.	The angular play bearing must be mounted without axial play.
A.	yes
B.	little tolerance is adjusted
C.	little tolerance is necessary
D.	can’t be stated
Answer» B. little tolerance is adjusted

Discussion

33.	Quality control charts doesn’t depend on which factor?
A.	normal distribution
B.	random sampling
C.	independence between samples
D.	binomial distribution
Answer» E.

Discussion

34.	Stress in a beam due to simple bending is
A.	directly proportional
B.	inversely proportional
C.	curvilinearly related
D.	none of the mentioned
Answer» B. inversely proportional

Discussion

35.	Cotter joint can be used to connect two rods for torque transmission purpose.
A.	true
B.	false
Answer» C.

Discussion

36.	Deep groove ball bearing has immense rigidity.
A.	true
B.	no it has point contact and hence low rigidity
C.	it has surface contact
D.	it has line contact
Answer» C. it has surface contact

Discussion

37.	For which of the following design factor of
A.	0.1
B.	1
C.	2 d) 0.9
Answer» D.

Discussion

38.	Taper rolling supports
A.	axial loads
B.	thrust loads
C.	both axial and thrust loads
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

39.	Determine the size of the bolts if yield strength of bolt is 400N/mm² and factor of safety is 4. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm. Also P=5kN acts at a distance of 200mm from the channel.
A.	14.34mm
B.	13.44mm
C.	15.44mm d) 12.66mm
Answer» C. 15.44mm d) 12.66mm

Discussion

40.	A curved beam with eccentricity 0.02D is loaded with 1kN.Centroidal radius=4D and inner and outer radii are 3.5D and 4.5D respectively. Area of cross section is 0.8D². Find the dimension D if allowable stress is 110N/mm² and considering only direct tensile stress.
A.	4.7mm
B.	6.8mm
C.	13.95mm
D.	3.4mm
Answer» E.

Discussion

41.	Woodruff key permits movement b/w shaft and the hub.
A.	axial
B.	radial
C.	eccentric
D.	none of the listed
Answer» C. eccentric

Discussion

42.	Which of the following statements is/are false for an axle?
A.	It is used to support rotating machine elements
B.	It can transmit torque
C.	It is subjected to axial force
D.	All of the above
Answer» C. It is subjected to axial force

Discussion

43.	Which material cannot be used to manufacture shafts?
A.	Plain carbon steels
B.	Cast iron
C.	Both a. and b.
D.	None of the above
Answer» C. Both a. and b.

Discussion

44.	Which type of key consists of two square tapered keys placed 90o apart?
A.	Tangent key
B.	Kennedy key
C.	Saddle key
D.	Woodruff key
Answer» C. Saddle key

Discussion

45.	In S-N diagram, the graph plotted between fatigue strength and number of stress cycles becomes horizontal for which type of materials?
A.	Ferrous materials
B.	Non-ferrous materials
C.	Both a. and b.
D.	None of the above
Answer» C. Both a. and b.

Discussion

46.	Calculate lead angle of a thread which has mean diameter of 45 mm and lead of 10 mm
A.	8.5o
B.	4.04o
C.	3.02o
D.	None of the above
Answer» C. 3.02o

Discussion

47.	Calculate overall efficiency of power screw, if the torque applied by the operator is 150 x 103to move a load of 30 kN through a distance of 10 mm
A.	22.36 %
B.	37.69 %
C.	31.83 %
D.	30.23 %
Answer» D. 30.23 %

Discussion

48.	Determine torque required to overcome collar friction in square threaded screw, if coefficient of friction is 0.12 and axial force of 20 kN is exerted by the screw. Mean radius of friction collar is 20 mm
A.	48000 N-mm
B.	120 N-mm
C.	4800 N-mm
D.	12000 N-mm
Answer» B. 120 N-mm

Discussion

49.	Which type of stress is induced in a screw thread ?
A.	Torsional shear stress
B.	Buckling load
C.	Bearing pressure
D.	All of the above
Answer» D. All of the above

Discussion

50.	A single start square threaded power screw supports  load of 30 kN which has outer diameter of 30 mm and a pitch of 8 mm. Maximum shear stress of 30 N/mm2 is induced in a screw body. Determine number of screw threads considering direct shear stress.
A.	3 threads
B.	2 threads
C.	4 threads
D.	None of the above
Answer» B. 2 threads

Discussion

Explore topic-wise MCQs in Testing Subject.

A knuckle joint can be used in valve mechanism of a reciprocating engine.

The strength of hollow shaft is more than the strength of solid shaft of same weight.

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.

Which of the following increases the dry strength of the sand?

Modulus of resilience is defined as

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.

Cylindrical load bearing has lower load capacity as compared to deep groove ball bearing.

If a clearance fit is present between shaft and hole, what is the tolerance on shaft or hole for a complete interchangeable approach?

When two hyperboloids are rotated, the resulting motion is

Active and inactive, both types of coils support the load although both don’t participate in spring action.

When the pitch angle is greater than 90⁰, it is called external bevel gear.

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.

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.

Quality checking of riveted joint is much expensive than that of welded joint.

Compressed length is smaller than the solid length.

If number of coils are 8 and wire diameter of spring 3mm, then solid length is given by?

There is problem of alignment in deep groove ball bearings.

Crown gears having a pitch angle of 90⁰

The stiffness of solid shaft is more than the stiffness of hollow shaft with same weight.

The ratio of the maximum fluctuation of energy to the ……. is called coefficient of fluctuation of energy.

Which of the following are characteristics of skew bevel gears?

1816/ [7200 x 10.8184 x 50] or σ=100.6N/mm².

In manual assembly, cost of screw is higher than the cost of driving a screw.

What is the amount of sea coal needed in cast irons for large green casting moulding sands?

The main advantage of sunk key is that it is a drive.

1816mm and radius of centroidal axis is 100mm, then find the bending stress at inner fibre whose radius is 50mm. Area of cross section of beam is 7200mm² and the beam is loaded with 100kN of load.

The safe stress for a hollow steel column which carries an axial load of 2100 kN is 125 MN/m2. if the external diameter of the column is 30cm, what will be the internal diameter?

A spring with index=15 is prone to buckling.

Maximum carbon content in welding is usually limited to

67 N/mm².; Spigot dia=65mm; thickness 0f collar=15mm

Calculate the diameter of pin from shear consideration with maximum shear stress allowed is 40NN/mm² and an axial tensile force of 50kN is acting on the rod.

The angular play bearing must be mounted without axial play.

Quality control charts doesn’t depend on which factor?

Stress in a beam due to simple bending is

Cotter joint can be used to connect two rods for torque transmission purpose.

Deep groove ball bearing has immense rigidity.

For which of the following design factor of

Taper rolling supports

Determine the size of the bolts if yield strength of bolt is 400N/mm² and factor of safety is 4. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm. Also P=5kN acts at a distance of 200mm from the channel.

A curved beam with eccentricity 0.02D is loaded with 1kN.Centroidal radius=4D and inner and outer radii are 3.5D and 4.5D respectively. Area of cross section is 0.8D². Find the dimension D if allowable stress is 110N/mm² and considering only direct tensile stress.

Woodruff key permits movement b/w shaft and the hub.

&nbsp;Which&nbsp;of&nbsp;the&nbsp;following&nbsp;statements&nbsp;is/are&nbsp;false&nbsp;for&nbsp;an&nbsp;axle?

Which&nbsp;material&nbsp;cannot&nbsp;be&nbsp;used&nbsp;to&nbsp;manufacture&nbsp;shafts?&nbsp;

&nbsp;Which&nbsp;type&nbsp;of&nbsp;key&nbsp;consists&nbsp;of&nbsp;two&nbsp;square&nbsp;tapered&nbsp;keys&nbsp;placed&nbsp;90o&nbsp;apart?&nbsp;

&nbsp;In&nbsp;S-N&nbsp;diagram,&nbsp;the&nbsp;graph&nbsp;plotted&nbsp;between&nbsp;fatigue&nbsp;strength&nbsp;and&nbsp;number&nbsp;of&nbsp;stress&nbsp;cycles&nbsp;becomes&nbsp;horizontal&nbsp;for&nbsp;which&nbsp;type&nbsp;of&nbsp;materials?&nbsp;

&nbsp;Calculate&nbsp;lead&nbsp;angle&nbsp;of&nbsp;a&nbsp;thread&nbsp;which&nbsp;has&nbsp;mean&nbsp;diameter&nbsp;of&nbsp;45&nbsp;mm&nbsp;and&nbsp;lead&nbsp;of&nbsp;10&nbsp;mm&nbsp;

Calculate&nbsp;overall&nbsp;efficiency&nbsp;of&nbsp;power&nbsp;screw,&nbsp;if&nbsp;the&nbsp;torque&nbsp;applied&nbsp;by&nbsp;the&nbsp;operator&nbsp;is&nbsp;150&nbsp;x&nbsp;103to&nbsp;move&nbsp;a&nbsp;load&nbsp;of&nbsp;30&nbsp;kN&nbsp;through&nbsp;a&nbsp;distance&nbsp;of&nbsp;10&nbsp;mm&nbsp;

&nbsp;Which&nbsp;type&nbsp;of&nbsp;stress&nbsp;is&nbsp;induced&nbsp;in&nbsp;a&nbsp;screw&nbsp;thread&nbsp;?&nbsp;

Which of the following statements is/are false for an axle?

Which material cannot be used to manufacture shafts?

Which type of key consists of two square tapered keys placed 90o apart?

In S-N diagram, the graph plotted between fatigue strength and number of stress cycles becomes horizontal for which type of materials?

Calculate lead angle of a thread which has mean diameter of 45 mm and lead of 10 mm

Calculate overall efficiency of power screw, if the torque applied by the operator is 150 x 103to move a load of 30 kN through a distance of 10 mm

Which type of stress is induced in a screw thread ?