Question Bank for Railways NTPC (Technical Ability) Automobile Engineering Automobile Engineering

The correct sequence of the given materials in ascending order of their Weldability is:

A)

1 and 2

B)

1 and 3

C)

2 alone

D)

1, 2 and 3

View Solution

5)

A)

MS, copper, cast iron, aluminium

B)

Cast iron, MS, aluminium copper

C)

Copper, cast iron, MS, aluminium

D)

Aluminium, copper, cast iron, MS

View Solution

6)

A screw thread specified by \[M\,\,20\times 25\,\,C\] as per BIS thread system means:

A)

Metric thread of 20 mm nominal diameter and 2.5 mm pitch having coarse tolerance

B)

Metric thread of 20 mm root diameter and 2-5 mm pitch having coarse tolerance

C)

Metric thread of fine class having 20 mm root diameter and 2.5 mm pitch

D)

Metric thread of 20 mm shank diameter and 25 mm thread depth with coarse tolerance.

View Solution

7)

Which one of the following statements is correct?

A)

No Flux is used in gas welding of mild steel

B)

Borax is the commonly used flux coating on welding electrodes

C)

Laser beam welding employs a vacuum chamber and thus avoids use of a shielding method

D)

AC can be used for GTAW process

View Solution

8)

Which one of the following statements with regard to belt drives is not correct?

A)

Increase in the angle of wrap of the belt enables more power transmission

B)

Maximum power is transmitted when the centrifugal tension is three times the tight side tension

C)

Wide and thin belt is preferable for better life than a thick and narrow one

D)

Crown is provided on the pulley to make the belt run centrally on the pulley

View Solution

9)

Angle of twist of a shaft of diameter d? is inversely proportional to:

A)

d

B)

\[{{d}^{2}}\]

C)

\[{{d}^{3}}\]

D)

\[{{d}^{4}}\]

View Solution

10)

Which one of the following sets of parameters should be monitored for determining safe operation of journal bearing?

A)

Oil pressure, bearing metal temperature and bearing vibration

B)

Bearing vibration, oil pressure and speed or shaft

C)

Bearing metal temperature oil pressure

D)

Oil pressure and bearing vibration.

View Solution

11)

The performance of a hydrodynamic journal bearing is a function of:

A)

Reynolds number

B)

Sommerfield number

C)

Speed

D)

Bearing modulus

View Solution

12)

Match List-I (Nature of Failure) with List-II (Nature of Member) and select the correct answer using the codes given below the lists:

List-I (Nature of failure)		List-II (Nature of Member)
A.	Structural member fails in axial compression	1.	Knuckle Joint
B.	A member fail along a \[45{}^\circ \] helical plane subjected to torsion	2.	Long column
C.	A structural member bends and collapses under axial compression load	3.	Strut
D.	A member fails in double shear for a joint	4.	Cast iron round bar subjected to torsion

Which one of the following correctly relates the life of a roller bearing in millions of revolutions (L) the load P and the basic dynamic load rating for 1 million revolutions C?

A)

A\[\to \]3, B\[\to \]1, C\[\to \]2, D\[\to \]4

B)

A\[\to \]2, B\[\to \]4, C\[\to \]3, D\[\to \]1

C)

A\[\to \]3, B\[\to \]4, C\[\to \]2, D\[\to \]1

D)

A\[\to \]2, B\[\to \]1, C\[\to \]3, D\[\to \]4

View Solution

13)

A)

\[L={{(C/P)}^{3}}\]

B)

\[L={{(C/P)}^{10/3}}\]

C)

\[L={{(P/C\,)}^{3}}\]

D)

\[L={{(C/P)}^{1/3}}\]

View Solution

14)

Match List-I with List-II and select the correct answer using the codes given below the lists:

List-I (Type of Thread)		List-II (Use)
A.	Square thread	1.	Used in vice
B.	Acme thread	2.	Used in lead screw
C.	Buttress thread	3.	Used in screw jack
D.	Trapezoidal thread	4.	Used in power transmission devices in machine tool

The number of slots in a 25 mm castle nut are:

A)

A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1

B)

A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4

C)

A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4

D)

A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1

View Solution

15)

A)

2

B)

4

C)

6

D)

8

View Solution

16)

Which key is preferred for the condition where a large amount of impact torque is to be transmitted in both direction of rotation:

A)

Woodruff key

B)

Feather key

C)

Gib-head key

D)

Tangent key

View Solution

17)

Which of the following is true about following specifications: Hex Bolt M 16 NL-IS: 1363:

A)

16 eye bolts used on electric motors

B)

A stress relieved blot for connecting rod

C)

A bolt with a nut

D)

A bolt with a nut and a lock nut

View Solution

18)

Which bearing is preferred for oscillating conditions?

A)

Double row roller hearing

B)

Angular contact single row ball bearing

C)

Taper roller bearing

D)

Needle roller hearing

View Solution

19)

Ball bearings are provided with a cage:

A)

To reduce friction

B)

To maintain the halls at a fixed distance apart

C)

To prevent the lubricant from flowing out

D)

To facilitate slipping of balls.

View Solution

20)

Thick steel plate cut with oxygen normally shows signs of cracking. This tendency for cracking can be minimized by:

A)

Slow speed cutting

B)

Cutting in two or more stages

C)

Preheating the plate

D)

Using oxy-acetylene flame

View Solution

21)

Jewel bearings are used in:

A)

Contaminated atmosphere

B)

low-torque applications

C)

Fully immersed in water condition

D)

High speed shafts

View Solution

22)

Match List-I with List-II and select the correct answer using the codes given below the lists:

List-I (Type of joint)		List-II (Mode of joining members)
A.	Cotter joint	1.	Connects two rods or bars permitting small amount of flexibility
B.	Knuckle joint	2.	Rigidly connects two members
C.	Turn buckle	3.	Connects two rods having threaded ends
D.	Riveted joint	4.	Permanent fluid-tight joint between two plates.
		5.	Connects two shafts and transmits torque

The most efficient riveted joint possible is one which would be as strong in tension, shear and bearing as the original plates to be joined. But this can never be achieved because:

A)

A\[\to \]5, B\[\to \]1, C\[\to \]3, D\[\to \]2

B)

A\[\to \]2, B\[\to \]1, C\[\to \]3, D\[\to \]4

C)

A\[\to \]5, B\[\to \]3, C\[\to \]2, D\[\to \]4

D)

A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4

View Solution

23)

A)

Rivets cannot be made with the same material

B)

Rivets are weak in compression

C)

There should be at least one hole in the plate reducing its strength

D)

Clearance is present between the plate and the rivet

View Solution

24)

Which of the following stresses are associated with the tightening of a nut on a stud?

A)

Tensile stresses due to stretching of stud.

B)

Bending stresses of stud.

C)

Transverse shear stresses across threads.

D)

Torsional shear stresses in threads due to frictional resistance

View Solution

25)

The frictional torque for square thread at mean radius while raising load is given by \[(W=load,\,{{R}_{0}}\,=\,\]Mean Radius,\[\phi =\]Angle of friction, \[\alpha \,=\,\]Helix angle):

A)

\[W{{R}_{0}}\tan (\phi -\alpha )\]

B)

\[W{{R}_{0}}\tan (\phi +\alpha )\]

C)

\[W{{R}_{0}}\tan \alpha \]

D)

\[W{{R}_{0}}\tan \phi \]

View Solution

26)

In a belt drive, if the pulley diameter is doubled keeping the tension and belt width constant, then it will be necessary to:

A)

Increase the key length

B)

Increase the key depth

C)

Increase the key width

D)

Decrease the key length

View Solution

27)

For improving the fatigue strength of steel. Of the above statements:

1. Grinding

2. Coating

3. Hammer peening

A)

1 and 2 are correct

B)

2 and 3 are correct

C)

1 and 3 are correct

D)

1, 2 and 3 are correct.

View Solution

28)

The following data refers to an open belt drive:

	Pulley A	Pulley B
Purpose?.	Driving	Driving
Diameter?.	450 mm	750 mm
Angle of contact?.	\[{{\theta }_{A}}\,=\,150\]	\[{{\theta }_{B}}\,=\,210{}^\circ \]
Coefficient of friction between belt and pulley	\[{{f}_{A}}\,=\,0.36\]	\[{{f}_{B}}\,=\,0.22\]

The ratio of tensions may be calculated using the Relation \[({{T}_{1}}/{{T}_{2}})\,=\]exp (z) where z is:

A)

\[{{f}_{A}}{{\theta }_{A}}\]

B)

\[{{f}_{B}}{{\theta }_{B}}\]

C)

\[({{f}_{A}}+{{f}_{B}})\,({{\theta }_{A}}+{{\theta }_{B}})/4\]

D)

\[({{f}_{A}}{{\theta }_{A}}+{{f}_{B}}{{\theta }_{B}})/2\]

View Solution

29)

In a multiple V-belt drive, when angle belt is damaged, it is preferable to change the complete set to:

A)

Reduce vibration

B)

Reduce slip

C)

Ensure uniform loading

D)

Ensure proper alignment

View Solution

30)

Design of shafts made of brittle material is based on:

A)

Guest's theory

B)

Rankine's theory

C)

St. Venant's theory

D)

Von-Mises theory.

View Solution

31)

A motor car has wheel base of 280 cm and the pivot distance of front stub axles is 140 cm. When the outer wheel has turned through 30, the angle of turn of the inner front wheel for correct steering will be:

A)

\[60{}^\circ \]

B)

\[{{\cot }^{-1}}2.23\]

C)

\[{{\cot }^{-1}}1.232\]

D)

\[30{}^\circ \]

View Solution

32)

Match List-I with List-II and select answer using the codes given below the Lists:

List-I (Types of joints)		List-II (An element of the joint)
A.	Riveted joint	1.	Pin
B.	Welded joint	2.	Strap
C.	Bolted joint	3.	Lock washer
D.	Knuckle joint	4.	Fillet

Consider the following statements regarding power screws:

A)

A\[\to \]4, B\[\to \]3, C\[\to \]2, D\[\to \]1

B)

A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1

C)

A\[\to \]2, B\[\to \]4, C\[\to \]3, D\[\to \]1

D)

A\[\to \]2, B\[\to \]4, C\[\to \]1, D\[\to \]3

View Solution

33)

1. The efficiency of a self-locking screw cannot be more than 50%

2. If the friction angle is less than the helix angle of the screw, then the efficiency will be more than 50%

3. The efficiency of ACME (trapezoidal) thread is less than that of square thread.

Electron beam welding can be carried out in:

A)

1, 2 and 3-are correct

B)

2 and 3 are correct

C)

1 and 3 are correct

D)

1 and 2 are correct

View Solution

34)

A)

Open air

B)

A shielding gas environment

C)

A pressurized inert gas chamber

D)

Vacuum

View Solution

35)

Given that \[p\,=\] chain pitch C = Centre distance N, n = number of teeth on large and small sprocket respectively, The length of chain in terms of pitches can be approximated by:

A)

\[\frac{2C}{P}\]

B)

\[\frac{2C}{P}+(N+n)/2\]

C)

\[\frac{2C}{P}+\left[ \frac{N+n}{2\pi } \right]\frac{p}{C}\]

D)

\[\frac{2C}{P}+\frac{N+n}{2p}{{\left[ \frac{N-n}{2p} \right]}^{2}}\,\frac{p}{C}\]

View Solution

36)

When compared to a rod of the same diameter and material, a wire rope:

A)

Is less flexible

B)

Has a much smaller load carrying capacity

C)

Does not provide much warning before failure

D)

Provides much greater time for remedial action before failure

View Solution

37)

A shafts subjected to fluctuating loads for which the normal torque (T) and bending moment (M) are 1000 N-m add 500 N-m respectively. If the combined shock and fatigue factor for bending is 1.5 and combined shock and fatigue factor for torsion is 2, then the equivalent twisting moment for the shaft is:

A)

2000-N-m

B)

2050 N-m

C)

2100 N-m

D)

2136 N-m

View Solution

38)

The lead angle of a worm is \[22.5{}^\circ .\] Its helix angle will be:

A)

\[22.5{}^\circ \]

B)

\[45{}^\circ \]

C)

\[67.5{}^\circ \]

D)

\[90{}^\circ \]

View Solution

39)

Consider the following statements about anti- friction bearings:

1. They have low starting and low running friction at moderate speeds

2. They have high resistance to shock loading.

3. They can carry both radial and thrust loads.

4. Their initial cost is high.

5. They can accommodated some amount of misalignment of shaft.

The load cup of a screw jack is made separate from the head of the spindle to:

A)

1, 2, 3 and 4

B)

1, 3 and 4 are correct

C)

1, 4 and 5 are correct

D)

1, 2, 3 and 5 are correct

View Solution

40)

A)

Enhance the load carrying capacity of the jack

B)

Reduce the effort needed for lifting the working load

C)

Reduce the value of frictional torque to be countered for lifting the load

D)

Prevent the rotation of load being lifted

View Solution

41)

A bolt of uniform strength can be developed by:

A)

Keeping the core diameter of threads equal to the diameter of unthreaded portion of the bolt.

B)

Keeping the core diameter smaller than the diameter of the unthreaded portion.

C)

Keeping the nominal diameter of threads equal the diameter of unthreaded portion of the bolt.

D)

One end fixed and the other end free.

View Solution

42)

Which designing a screw is a screw jack against buckling failure, the end conditions for the screw are taken as:

A)

Both the ends fixed

B)

Both the ends hinged

C)

One end fixed and other end hinged

D)

One end fixed and there end free

View Solution

43)

Match List-I with List-II and select the correct answer using the codes given below the list:

List-I (Different types of detachable joints)		List-II (Specific use of these detachable joints)
A.	Cotter joint	1.	Tie rod of a wall crane
B.	Knuckle joint	2.	Suspension bridges
C.	Suspension link joint	3.	Diagonal stays in boiler
D.	Turn buckle (adjustable joint)	4.	Cross-head a steam engine

A spur gear transmitting power is connected to the shaft with a key of rectangular section. The type (s) of stresses developed in the key is/are:

A)

A\[\to \]4, B\[\to \]2, C\[\to \]3, D\[\to \]1

B)

A\[\to \]4, B\[\to \]3, C\[\to \]2, D\[\to \]1

C)

A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4

D)

A\[\to \]2, B\[\to \]1, C\[\to \]4, D\[\to \]3

View Solution

44)

A)

Shear stress alone

B)

Hearing stress alone

C)

Both shear and bearing stresses

D)

Shearing, bearing and bending stresses.

View Solution

45)

The permissible stress in a filled weld is 100 N/mm. The fillet weld has equal leg lengths of 15 mm each. The allowable shearing load on weldment per cm length of the weld is:

A)

225 kN

B)

15.0 kN

C)

10.6 kN

D)

7.5 kN

View Solution

46)

Sources of power loss in a chain drive are given below:

1. Friction between chain and sprocket teeth.

2. Overcoming the chain stiffness.

3. Overcoming the friction in shaft bearing.

4. Frictional resistance of the motion of the chain in air or lubricant.

The correct sequence of descending order of power loss due to these sources is:

A)

1, 2, 3, 4

B)

1, 2, 4, 3

C)

2, 1, 3, 4

D)

2, 1, 4, 3

View Solution

47)

Consider the following design considerations:

The design of the pin of a rocker arm of an I.C. engine is based on:

A)

1, 2 and 4

B)

1, 3 and 4

C)

2, 3 and 5

D)

3, 4 and 5

View Solution

48)

Which one of the following loadings is considered for design of axles?

A)

Bending moment only

B)

Twisting moment only

C)

Combined bending moment and torsion

D)

Combined action of bending moment, twisting moment and axial thrust.

View Solution

49)

Removal of metal particles from the raceway of a roiling contact bearing is a kind of failure of bearing known as:

A)

Pitting

B)

Wearing

C)

Spilling

D)

Scuffing

View Solution

50)

The design calculations of members subject to fluctuating loads with the same factor of safety yield the most conservative estimates when using:

A)

Gerber relation

B)

Soderberg relation

C)

Goodman relation

D)

None of the above

View Solution

51)

Match List-I with List-II and select the correct answer using the codes given below the lists:

List-I		List-II
A.	Crank shaft	1.	Supports the revolving part and transmits torque.
B.	Wire shaft	2.	Transmits motion between shafts where is not possible to effect rigid coupling between them.
C.	Axle	3.	Converts linear motion into rotary motion.
D.	Plain shaft	4.	Supports only the revolving parts.

Match List-I with List-II and select the correct answer using the codes given below the lists:

A)

A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4

B)

A\[\to \]4, B\[\to \]2, C\[\to \]3, D\[\to \]1

C)

A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1

D)

A\[\to \]1, B\[\to \]4, C\[\to \]2, D\[\to \]3

View Solution

52)

List-I (Terminology)		List-II (Relevant term)
A.	Interference	1.	Arc of approach, arc of recess, circular pitch.
B.	Dynamic load on tooth	2.	Lewis equation.
C.	Static load	3.	Minimum number of teeth on pinion.
D.	Contact ratio	4.	Inaccuracies in tooth profile

Match List-I with List-II and select the correct answer using the codes given below the lists:

A)

A\[\to \]3, B\[\to \]4, C\[\to \]1, D\[\to \]2

B)

A\[\to \]1, B\[\to \]2, C\[\to \]3, D\[\to \]4

C)

A\[\to \]4, B\[\to \]3, C\[\to \]2, D\[\to \]1

D)

A\[\to \]3, B\[\to \]4, C\[\to \]2, D\[\to \]1

View Solution

53)

List-I (Name)		List-II (Type)
A.	Oldham coupling	1.	Joins collinear shafts and is rigid type.
B.	Flange coupling	2.	Joins non-collinear shafts and is adjustable.
C.	Universal coupling	3.	Joins collinear shafts and engages and disengages them during motion.
D.	Friction coupling	4.	Compensates peripheral shafts, longitudinal and angular shifts of shafts.

Match List-I with List-II and select the correct answer using the codes given below the lists:

A)

A\[\to \]2, B\[\to \]1, C\[\to \]4, D\[\to \]3

B)

A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4

C)

A\[\to \]1, B\[\to \]4, C\[\to \]2, D\[\to \]3

D)

A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4

View Solution

54)

List-I (Requirement)		List-II (Type)
A.	High temperature service.	1.	Teflon bearing
B.	High load	2.	Carbon bearing
C.	No lubrication	3.	Hydrodynamic bearing
D.	Bushings	4.	Sleeve bearing

In the calculation of induced shear stress in helical springs, the Wahl's correction factor is used to take care of:

A)

A\[\to \]1, B\[\to \]2, C\[\to \]3, D\[\to \]4

B)

A\[\to \]4, B\[\to \]1, C\[\to \]2, D\[\to \]3

C)

A\[\to \]2, B\[\to \]1, C\[\to \]3, D\[\to \]4

D)

A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4

View Solution

55)

A)

Combined effect of transverse shear stress and bending stress in the wire.

B)

Combined effect of bending stress and curvature of the wire.

C)

Combined effect of transverse shear stress and curvature of the wire.

D)

Combined effect of torsional shear stress an transverse shear stress in the wire

View Solution

56)

Two rigid plates are clamped by means of bolt and nut with an initial force N. After tightening, separating force P (P<N) is applied to the Lower plate, which in turn ads on nut. The tension in the bolt after this is:

A)

(N+P)

B)

\[\left( N-P \right)\]

C)

P

D)

N

View Solution

57)

To ensure self-locking in a screw jack it is essential that helix angle is:

A)

Larger than friction angle

B)

Smaller than friction angle

C)

Equal to friction angle

D)

Such as to give maximum efficiency in lifting

View Solution

58)

A double fillet welded joint with parallel fillet weld of length L and leg B is subjected to a tensile force P. Assuming uniform stress distribution, the shear stress in distribution, the shear stress the weld is given by:

A)

\[\frac{\sqrt{2.}\,P}{BL}\]

B)

\[{{\sigma }_{1}}=\frac{P}{2hl}\]

C)

\[\frac{P}{\sqrt{2.}B.L}\]

D)

\[\frac{2P}{B.L}\]

View Solution

59)

In flat belt drive, if the slip between the driver and the belt is 1%, that between belt and follower is 3% and driver and follower pulley diameters are equal, then the velocity ratio of the drive will be:

A)

0.99

B)

0.98

C)

0 0.97

D)

0.96

View Solution

60)

Effective stress in wire ropes during normal working is equal to the stress due to:

A)

Axial load plus stress due to bending

B)

acceleration/retardation of masses plus stress due to bending

C)

Axial load plus stress due to acceleration/ retardation

D)

bending plus stress due to acceleration/retardation

View Solution

61)

A transmission shaft subjected to bending loads must be designed on the basis of:

A)

Maximum normal stress theory

B)

Maximum shear stress theory

C)

Maximum normal stress and maximum shear stress theories

D)

Fatigue strength

View Solution

62)

The form factor of a spur gear tooth depends upon the

1. Number of teeth

2. Pressure angle.

3. Addendum modification.

4. Circular pitch.

When belt drive is transmitting maximum power:

A)

1 and 3 are correct

B)

1 and 4 are correct

C)

1, 2 and 3 are correct

D)

1 and 4 are correct

View Solution

63)

A)

Effective tension is equal to centrifugal tension

B)

Effective tension is half of centrifugal tension

C)

Driving tension on slack side is equal to the centrifugal tension

D)

Driving tension on tight side is twice the centrifugal tension

View Solution

64)

Tapered roller bearing can take:

A)

Radial load only

B)

Axial load only

C)

Both radial and axial loads and the ratio of these being less than unity

D)

Both radial and axial loads and the ratio of these being greater than unity

View Solution

65)

In bearing characteristic number in a hydrodynamic bearing depends on:

A)

It is closer to real life situation

B)

It leads to a safer design

C)

It leads to cost effective design

D)

No other assumption is possible

View Solution

66)

The bearing characteristic number in a hydrodynamic bearing depends on:

A)

Length, width and load

B)

Length, width and speed

C)

Viscosity, speed and load

D)

Viscosity, speed and bearing pressure

View Solution

67)

Which one of the following welding processes uses non-consumable electrodes?

A)

TIG welding

B)

MIG welding

C)

Manual arc welding

D)

Submerged arc welding

View Solution

68)

Match List-I with List-II and Select the correct answer using the codes given below the Lists:

List-I (Filler)		List-II (Joining process)
A.	Cu, Zn, Ag, alloy	1.	Braze welding
B.	Cu, Sn alloy	2.	Brazing
C.	Pb, Sb alloy	3.	Soldering
D.	Iron oxide and aluminium powder	4.	TIG welding of aluminium.

The maximum efficiency of a self-locking screw is:

A)

A\[\to \]1, B\[\to \]1, C\[\to \]1, D\[\to \]3

B)

A\[\to \]4, B\[\to \]2, C\[\to \]3, D\[\to \]4

C)

A\[\to \]2, B\[\to \]1, C\[\to \]2, D\[\to \]3

D)

A\[\to \]2, B\[\to \]4, C\[\to \]2, D\[\to \]3

View Solution

69)

A)

50%

B)

70%

C)

75%

D)

80%

View Solution

70)

Match List-I (Type of keys) with List-II (Characteristic) and select the correct answer using the codes given below the Lists:

List-I		List-II
A.	Woodruff key	1.	Loose fitting, light duty
B.	Kennedy key	2.	Heavy duty
C.	Feather key	3.	Self-aligning
D.	Flat key	4.	Normal industrial use

A)

A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4

B)

A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4

C)

A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1

D)

A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1

View Solution

71)

2. Non-consumable electrode

MIG welding process uses

1. Consumable electrode

3. D. C power supply

4. A. C power supply.

In the case of a vertical belt pulley drive with \[{{T}_{C}}\] as centrifugal tension and \[{{T}_{0}}\] as the initial tension, the belt would tend to hang clear of the lower pulley when:

A)

2 and 4 are correct

B)

2 and 3 arc correct

C)

1 and 4 are correct

D)

1 and 3 are correct

View Solution

72)

A)

\[{{T}_{c}}\]<\[{{T}_{0}}\]

B)

\[{{T}_{c}}\,=\,{{T}_{0}}/3\]

C)

\[{{T}_{c}}\]>\[{{T}_{0}}\]

D)

\[{{T}_{c}}\,=\,{{T}_{0}}/2\]

View Solution

73)

Given that \[{{T}_{1}}\] and \[{{T}_{2}}\] are the tensions on the tight and slack of the belt respectively, the initial tension of the belt taking centrifugal tension \[{{T}_{c}}\] is equal to:

A)

\[\frac{{{T}_{1}}+{{T}_{2}}+{{T}_{c}}}{3}\]

B)

\[\frac{{{T}_{1}}+{{T}_{2}}+2{{T}_{c}}}{2}\]

C)

\[\frac{{{T}_{1}}+{{T}_{2}}+3{{T}_{c}}}{2}\]

D)

\[\frac{{{T}_{1}}+{{T}_{2}}+4{{T}_{c}}}{3}\]

View Solution

74)

Given that W = weight of load handled, W = weight of rope, and \[f=\] acceleration, the additional load in ropes of a hoist during starting is given by:

A)

\[{{F}_{a}}=\left( \frac{W-{{W}_{r}}}{g} \right)f\]

B)

\[{{F}_{a}}=\left( \frac{W+{{W}_{r}}}{g} \right)f\]

C)

\[{{F}_{a}}=\left( \frac{W}{g} \right)f\]

D)

\[{{F}_{a}}=\left( \frac{{{W}_{r}}}{g} \right)f\]

View Solution

75)

When a shaft transmits power through gears, the shaft experiences:

A)

Torsional stresses alone

B)

Bending stresses alone

C)

Constant bending and varying torsional stresses

D)

Varying bending and constant torsional stresses

View Solution

76)

The limiting wear load of spur gear is proportional to (where \[{{E}_{p}}\,\,=\] Young's modulus of union material; \[{{E}_{g}}\,\,=\] Young's modulus of gear material:

A)

\[{{({{E}_{p}}+{{E}_{g}})}^{-1}}\]

B)

\[\left( \frac{{{E}_{p}}+{{E}_{s}}}{{{E}_{p}}{{E}_{s}}} \right)\]

C)

\[\left( 1+\frac{{{E}_{p}}}{{{E}_{s}}} \right)\]

D)

\[\left( 1+\frac{{{E}_{g}}}{{{E}_{B}}} \right)\]

View Solution

77)

Which one of the following statements is not true of rolling contact bearing?

A)

The bearing characteristic number is given by \[\frac{ZN}{p}\] where Z is the absolute viscosity of the lubricant, Nis the shaft speed and p is the bearing pressure.

B)

Inner race of a radial ball bearing has an interference fit with the shaft and rotates along with it.

C)

Outer race of the hearing has in interference fit with bearing housing and does not rotate.

D)

In some cases, the inner race is stationary and outer race rotates.

View Solution

78)

In the multiple disc clutch, if there are 6 discs on the driving shaft and 5 discs on the driven shaft, then the number of pairs of contact surfaces will be equal to:

A)

11

B)

12

C)

10

D)

22

View Solution

79)

Match List-I with List-II and select the correct answer using the codes given below the lists:

List-I (Bearing materials)		List-II (Properties)
A.	Babbits	1.	Porous
B.	Bronze	2.	Good emeddability
C.	C.I.	3.	Suitable for high Loads and low speeds
D.	Sintered powdered metal	4	Run well with C.I. journals

Wahl stress factor takes into account:

A)

A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1

B)

A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4

C)

A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4

D)

A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1

View Solution

80)

A)

Direct shear stress.

B)

Torsional shear stress

C)

Wire curvature effect

D)

Direct shear and wire curvature effect.

View Solution

81)

Which of the following stresses are associated with the tightening of nut on a bolt?

(1) Tensile stress due to the stretching of bolt

(2) Bending stress due to the bending of bolt

(3) Crushing and shear stresses in threads

(4) Torsional shear stress due to frictional resistance between the nut and the bolt.

Select the correct answer using the codes given below:

A)

1, 2 and 4

B)

1, 2 and 3

C)

2, 3 and 4

D)

1, 3 and 4

View Solution

82)

The shearing area of a key of length 'L' breadth 'b' depth 'h' is equal to:

A)

\[b\times h\]

B)

\[L\times h\]

C)

\[L\times b\]

D)

\[L\times (h/2)\]

View Solution

83)

Match List-I (Machine element) with List-II (Cause of failure) and select the correct answer using the codes given below the lists:

List-I		List-II
A.	Axle	1.	Shear stress
B.	Cotter	2.	Tensile/Compressive stress
C.	Connecting rod	3.	Wear
D.	Journal bearing	4	Bending stress

In oxy-acetylene gas welding, for complete combustion, the volume of oxygen required per unit of acetylene is:

A)

A\[\to \]1, B\[\to \]4, C\[\to \]2, D\[\to \]3

B)

A\[\to \]4, B\[\to \]1, C\[\to \]2, D\[\to \]3

C)

A\[\to \]4, B\[\to \]1, C\[\to \]3, D\[\to \]2

D)

A\[\to \]1, B\[\to \]4, C\[\to \]3, D\[\to \]2

View Solution

84)

A)

1

B)

1.5

C)

2

D)

2.5

View Solution

85)

Consider the following statements. A splined shaft is used for

1. Transmitting power

2. Holding a flywheel rigidly in position

3. Moving axially the gear wheels mounted on it

4. Mounting V-belt pulleys on it.

When two shafts are neither parallel nor intersecting, power can be transmitted by using:

A)

2 and 3 are correct

B)

1 and 4 are correct

C)

2 and 4 are correct

D)

1 and 3 are correct

View Solution

86)

A)

A pair of spur gears

B)

A pair of helical gears

C)

An Oldham's coupling

D)

A pair of spiral gears.

View Solution

87)

In the assembly design of shaft, pulley and key, the weakest members is:

A)

Pulley

B)

Key

C)

Shaft

D)

None

View Solution

88)

In the formulation of Lewis equation for toothed gearing, it is assumed that tangential tooth load \[{{F}_{1}}\]act on the:

A)

Pitch point

B)

Tip of the tooth

C)

Root of the tooth

D)

Whole face of the tooth

View Solution

89)

For a two-dimensional state \[({{\sigma }_{1}},\,{{\sigma }_{2}},\,{{\sigma }_{1}}\]>\[0,\,{{\sigma }_{2}}\]<0) he designed values are most conservative if which one of the following failure theories were used?

A)

Maximum principal strain theory

B)

Maximum distortion energy theory

C)

Maximum shear stress theory

D)

Maximum principal stress theory

View Solution

90)

Match List-I with List-II and select the correct answer using the codes given below the lists:

List-I		List-II
A.	Single-plate friction clutch	1.	Scooters clutch
B.	Multi-plate friction clutch	2.	Rolling mills
C.	Centrifugal clutch	3.	Trucks
D.	Jaw clutch	4.	Mopeds

Which of the following stresses are associated with the design of pins in hushed pin-type, flexible coupling?

A)

A\[\to \]1, B\[\to \]3, C\[\to \]4, D\[\to \]2

B)

A\[\to \]1, B\[\to \]3, C\[\to \]2, D\[\to \]4

C)

A\[\to \]3, B\[\to \]1, C\[\to \]2, D\[\to \]4

D)

A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]2

View Solution

91)

1. Bearing stress

2. Bending stress

3. Axial tensile stress

4. Transverse shear stress

Select the correct answer using the codes given below:

A)

1, 3 and 4

B)

2, 3 and 4

C)

1, 2 and 3

D)

1, 2 and 4

View Solution

92)

The diameter of tommy bar for a screw jack is designed for:

A)

Bending moment due to effort applied

B)

Torque on the tommy bar due to effort applied

C)

A percentage of axial loads

D)

Some axial loads coupled with transverse loads

View Solution

93)

Centrifugal tension in belts is:

A)

Useful because it maintains some tension even when no power is transmitted

B)

Not harmful because it does not take part in power transmission

C)

Harmful because it increases belt tension and reduces the power transmitted

D)

A hypothetical phenomenon and does not actually exist in belts

View Solution

94)

In a single reduction, a large velocity ratio is required. The best transmission is:

A)

Spur gear drive

B)

Helical gear drive

C)

Bevel gear drive

D)

Worm gear drive

View Solution

95)

Which one of the following belts should not he used above\[40{}^\circ C\]?

A)

Balata belt

B)

rubber belt

C)

Fabric belt

D)

synthetic belt

View Solution

96)

A nomenclature \[\phi \]50H8/p8 denoted that

1. Hole diameter is 50 mm

2. It is a shaft base system

3. 8 indicates fundamental deviation.

Which of the statements given above is/are correct?

A)

1, 2 and 3

B)

1 and 2 only

C)

1 and 3 only

D)

3 only

View Solution

97)

A certain minimum number of teeth is to be kept for a gear wheel:

A)

So that the gear is of a good size

B)

For better durability

C)

To avoid interference and undercutting

D)

For better strength

View Solution

98)

In a single row deep groove ball-bearing, cages are needed to:

A)

Separate the two races

B)

Separate the balls from the inner race

C)

Separate the outer race from the balls

D)

Ensure that the balls do into cluster at one point and maintain proper relative angular positions.

View Solution

99)

Which one of the following types of bearings is employed in shafts of gearboxes of automobiles?

A)

Hydrodynamic journal bearings

B)

Multi-lobed journal hearings

C)

Antifriction bearings

D)

Hybrid journal bearings.

View Solution

100)

A hole is to be punched in a 15 mm thick plate having an ultimate shear strength of 3 N-\[m{{m}^{-2}}.\]If the allowable crushing stress in the punch is \[6\,N\]-\[m{{m}^{-2}},\] the diameter of the smallest hole which can be punched is equal to:

A)

15 mm

B)

30 mm

C)

60 mm

D)

120 mm

View Solution

101)

The edge of a steel plate cut by oxygen cutting will get hardened when the carbon content is:

A)

Less than 0.1 percent

B)

Less than 0.3 percent

C)

More than 0.3 percent

D)

Anywhere between 0.1 to 1.0 percent

View Solution

102)

The safe rim velocity of a flywheel is influenced by the

A)

Centrifugal stresses

B)

Fluctuation of energy

C)

Fluctuation of speed

D)

Mass of the flywheel

View Solution

103)

Match List-I (Bearings) with List-II (Applications) and select the correct answer using the codes given below the lists:

List-I		List-II
A.	Journal hearing	1.	Electric motors
B.	Thrust bearing	2.	Watches
C.	Conical pivot bearing	3.	Marine engines
D.	Ball bearing	4.	Swivelling chairs

Weld spatter occurs due to any of the following except:

A)

A\[\to \]3, B\[\to \]4, C\[\to \]1, D\[\to \]2

B)

A\[\to \]4, B\[\to \]2, C\[\to \]1, D\[\to \]3

C)

A\[\to \]3, B\[\to \]4, C\[\to \]2, D\[\to \]1

D)

A\[\to \]4, B\[\to \]2, C\[\to \]3, D\[\to \]1

View Solution

104)

A)

High welding current

B)

Too small an electrode

C)

Are

D)

Wrong polarity

View Solution

105)

In a hydrodynamic journal bearing, there is:

A)

A very thin film of lubricant between the journal and the hearing such that there is contact between the journal and the bearing

B)

A thick film of lubricant between the journal and the bearing

C)

No lubricant between the journal and the bearing

D)

A forced lubricant between the journal and the bearing

View Solution

106)

1. From design considerations, it is always advantageous to place cast iron ribs on the tension side rather than on the compression side.

2. Cast iron is an excellent choice for machine tool guides and frames

3. Cast iron parts have a low notch sensitivity.

Which of these statements are correct?

A)

1, 2 and 3

B)

2 and 3

C)

1 and 3

D)

1 and 2

View Solution

107)

Match List-I (Applications) with List-II (Choice of bearings) and select the correct answer using the codes given below the lists:

List-I (Application)		List-II (Choice of Bearings)
A.	Granite table of a coordinate measuring machine	1.	Hydrodynamic bearing
B.	Headstock spindle of a lathe	2.	Deep groove ball bearing
C.	Crank shaft of a lathe	3.	hydrostatic bearing diesel engine
D.	Armature of 0.5 kW induction motor	4.	Taper roller bearing

If k = 3 for hail bearings and k = 3.33 for roller bearings, which one of the following correctly states the load (P) - Life (L) relationship for rolling contact bearings?

A)

A\[\to \]1, B\[\to \]4, C\[\to \]3, D\[\to \]2

B)

A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4

C)

A\[\to \]1, B\[\to \]2, C\[\to \]3, D\[\to \]4

D)

A\[\to \]3, B\[\to \]4, C\[\to \]1, D\[\to \]2

View Solution

108)

A)

\[\frac{{{L}_{1}}}{{{L}_{2}}}\,=\,{{\left( \frac{{{p}_{1}}}{{{p}_{2}}} \right)}^{k}}\]

B)

\[\frac{{{L}_{1}}}{{{L}_{2}}}\,=\,{{\left( \frac{{{p}_{1}}}{{{p}_{2}}} \right)}^{\frac{1}{(k-1)}}}\]

C)

\[\frac{{{L}_{2}}}{{{L}_{1}}}\,=\,{{\left( \frac{{{p}_{1}}}{{{p}_{2}}} \right)}^{k}}\]

D)

\[\frac{{{L}_{2}}}{{{L}_{1}}}\,=\,{{\left( \frac{{{p}_{1}}}{{{p}_{2}}} \right)}^{k-1}}\]

View Solution

109)

Consider the following statements regarding boundary lubrication conditions in hydrodynamic journal hearings:

1. It is an undesirable condition.

2. It always occurs during starting and stopping of the journal.

3. It necessitates frequent repair of the journal.

4. This condition can he completely eliminated by using high viscosity lubricant.

Which of the statements given above are correct?

A)

1, 2 and 4

B)

2, 3 and 4

C)

1 and 2

D)

3 and 4

View Solution

110)

When the lubricating oil is forced between the journal and bearing by external pressure, the bearing is known as:

A)

Zero film bearing

B)

Boundary lubricated bearing

C)

Hydrostatic bearing

D)

Hydrodynamic bearing

View Solution

111)

Intensity of radiation at a surface in perpendicular direction is equal to:

A)

Product of emissivity of surface and \[1/\pi .\]

B)

Product of emissivity of surface and \[\pi .\]

C)

Product of emissive power of surface and \[1/\pi .\]

D)

Product of emissive power of surface and \[\pi .\]

View Solution

112)

In a mass transfer process of diffusion of hot smoke in cold air in a power plant, the temperature profile and the concentration profile will become identical when:

A)

Prandtl No. = 1

B)

Nusselt No. = 1

C)

Lewis No. = 1

D)

Schemidt No. = 1

View Solution

113)

Witch one of the following numbers represents the ratio of kinematic viscosity to the thermal diftusivity?

A)

Grashoff number

B)

Prandtl number

C)

Mach number

D)

Nusselt number.

View Solution

114)

After expansion from a gas turbine, the hot exhaust gases are used to heat the compressed air from a compressor with the help of a cross flow compact heat exchanger of 0.8 effectiveness. What is the number of transfer units of the heat exchanger?

A)

2

B)

4

C)

8

D)

16

View Solution

115)

A thin flat Plate \[2\,m\,\times \,2\,m\] is hanging freely in air. The temperature of the surrounding is \[25{}^\circ C.\] Solar radiation is falling on one side of the plate at the rate of 500 \[W/{{m}^{2}}.\] What should be the convective heat Transfer coefficient in \[W/{{m}^{2}}{}^\circ C,\] if the temperature of The plate is to remain constant at \[30{}^\circ C?\]

A)

25

B)

50

C)

100

D)

200

View Solution

116)

In order to achieve maximum heat dissipation, the fin should be designed in such a way that:

A)

It should have maximum lateral surface at the root side of the fin

B)

It should have maximum lateral surface towards the tip side of the fin

C)

It should have maximum lateral surface near the centre of the fin

D)

It should have minimum lateral surface near the centre of the fin.

View Solution

117)

A composite hollow sphere with steady internal heating is made of 2 layers of materials of equal thickness with thermal conductivities in the ratio of' 1:2 for inner to outer layers. Ratio of inside to outside diameter is 0.8. What is ratio of temperature drop across the inner and outer layers?

A)

0.4

B)

1.6

C)

2 in 0.8

D)

2.5

View Solution

118)

Upto the critical radius of insulation:

A)

Added insulation increases heat loss.

B)

Added insulation decreases heat loss.

C)

Convection heat loss is less than conduction heat loss.

D)

Heat flux decreases.

View Solution

119)

Match List-I (Governing Equations of Heat Transfer) with List-II (Specific Case of Heat Transfer) and select the correct answer using the code given below the lists:

List-I (Governing Equations of Heat Transfer)		List-II (Specific Cass of Heat Transfer)
A.	\[\frac{{{d}^{2}}T}{d{{r}^{2}}}\,+\,\frac{2dT}{rdr}\,=\,0\]	1.	Pin fin 1-D case
B.	\[\frac{{{\partial }^{2}}T}{\partial {{x}^{2}}}\,+\,\frac{1}{\alpha }\,\frac{\partial T}{dt}\]	2.	1-D conduction in cylinder
C.	\[\frac{{{d}^{2}}T}{d{{r}^{2}}}\,+\,\frac{1}{r}\,\frac{dT}{dr}\,=\,0\]	3.	1-D conduction in sphere
D.	\[\frac{{{d}^{2}}\theta }{d{{x}^{2}}}-{{m}^{2}}\theta =0\]	4.	Plane slab