← Junior Engineer
Past Questions
TIG welding is best suited for welding -
A)
Stainless steel
B)
Carbon steel
C)
Aluminium
D)
Silver
TIG welding gives excellent control and cleanliness, making it especially suitable for aluminium.
Hardness of steel greatly improves with -
A)
Annealing
B)
Tempering
C)
Normalising
D)
Cyaniding
Cyaniding introduces carbon and nitrogen into the surface and substantially increases surface hardness.
In perpetual inventory control, the material is checked as it reaches its -
A)
Minimum value
B)
Maximum value
C)
Average value
D)
Alarming value
Correct answer: D. Alarming value is the option that matches the standard principle or definition asked.
The coefficient of friction between the belt and pulley depends upon the -
A)
Material of belt and pulley
B)
Slip of belt
C)
Speed of belt
D)
Allofthese
Friction depends on material pair, slip, surface finish, speed; hence all factors.
The value of Poisson’s ratio for cast iron is -
A)
0.1 to 0.2
B)
0.23 to 0.27
C)
0.25 to 0.33
D)
0.4 to 0.6
Cast iron Poisson ratio ~0.23-0.27, steel ~0.27-0.30, rubber ~0.45.
The supply of working fluid to the engine to suit the load conditions is controlled by -
A)
Meyer’s expansion valve
B)
D-slide valve
C)
Flywheel
D)
Governor
The governor regulates the engine's working-fluid supply as load changes, maintaining approximately constant speed.
A continuous beam is one which is -
A)
Infinitely long
B)
Supported at two places
C)
Supported at one point
D)
Supported at more than two supports
Continuous beam rests on more than two supports, unlike simply supported.
Coefficient of fluctuation of speed is the -
A)
Variation of energy above and below the mean resisting toque line
B)
Difference between maximum and minimum energies
C)
Ratio ofthe maximum fluctuation of energy to the work done per cycle
D)
Ratio of maximum fluctuation of speed to the mean speed
The coefficient of fluctuation of speed is defined as the ratio of the maximum fluctuation of speed to the mean speed, i.e. (Nmax - Nmin)/Nmean. Hence option (d) is correct.
Why others are incorrect:
- (a) describes a variation in energy, not speed.
- (b) is the difference between maximum and minimum energies, which is the maximum fluctuation of energy.
- (c) is the coefficient of fluctuation of energy, not speed.
The materials having same elastic properties in all directions are called -
A)
Uniform materials
B)
Isotropic materials
C)
Elastic materials
D)
Ideal materials
Isotropic materials have the same elastic properties in every direction.
The stress at which extension of the material takes place more quickly as compared to the increase in load is called -
A)
Elastic point of the material
B)
Breaking point of the material
C)
Yielding point of the material
D)
Ultimate point of the material
Correct answer: C. Yielding point of the material is the option that matches the standard principle or definition asked.
If speed of a mechanism is to be reduced in the ratio 1000:1, which of the following systems would you choose?
A)
Bevel gear system
B)
Spur gear system
C)
Differential gear system
D)
Worm and worm wheel system
A worm-and-wheel drive provides very large speed reduction in a compact arrangement, suitable for ratios such as 1000:1.
Preheating is essential in welding -
A)
High speed steel
B)
Stainless steel
C)
Cast iron
D)
Aluminium
Correct answer: C. Cast iron is the option that matches the standard principle or definition asked.
A portable drilling machine is specified by -
A)
The size of the job it can hold
B)
Maximum diameter of drill it can hold
C)
Spindle speeds and feeds
D)
Maximum spindle travel
Portable drilling machines are commonly specified by the maximum drill diameter they can accommodate.
Internal or external tapers on a turret lathe can be turned by -
A)
Sliding attachment
B)
Morse taper attachment
C)
Taper turning attachment
D)
Face turning attachment
A taper-turning attachment is used to machine internal or external tapers on a turret lathe.
Damping capacity ofa material is its ability to -
A)
Absorb shock
B)
Absorb vibration
C)
Withstand compression
D)
Absorb impact load
Damping capacity is the ability of a material to absorb and dissipate vibrational energy, thereby reducing oscillations. So the correct option is **b. Absorb vibration**. Option **a** (absorb shock) is related to toughness or shock resistance, not specifically damping capacity. Option **d** (absorb impact load) also refers more to impact resistance/toughness. Option **c** (withstand compression) is a strength property, not a damping property.
Which of the following materials is most elastic?
A)
Rubber
B)
Plastic
C)
Steel
D)
Brass
Steel has highest Young's modulus and returns most, rubber has large strain but low elastic modulus; steel most elastic.
Screw used for power transmission should have -
A)
High efficiency
B)
Strong teeth
C)
Finished threads
D)
High efficiency and string teeth
Power screw needs high efficiency for transmission and strong teeth for load, so both.
When the relation between the controlling force (F1) and radius of rotation (r) for a spring controlled governor is F1 = ar+ b, then the governor will be -
A)
Stable
B)
Unstable
C)
Isochronous
D)
None of these
For a spring-controlled governor, controlling force increasing with radius gives a stable characteristic.
The Hooke’s joint consists of -
A)
Two forks
B)
One fork
C)
Three forks
D)
Four forks
Hooke's joint has two forks (driving and driven) plus cross centre block.
The most important objective behind plant layout is -
A)
Overall simplification, safety ofintegration
B)
Economy in space
C)
Maximum travel time in plan
D)
To provide conveniently located shops
Correct answer: A. Overall simplification, safety ofintegration is the option that matches the standard principle or definition asked.
Which of the following is the type of lathe machine?
A)
Jigs and fixtures
B)
Capstan
C)
Turret
D)
Both capstan and turret
Capstan and turret lathes are both types of turret lathes.
A beam of uniform strength is one in which -
A)
Bending moment is same throughout the beam
B)
Deflection is same throughout the length
C)
The bending stress is same in every section along the longitudinal axis
D)
Shear stress is uniform throughout the beam
A beam of uniform strength is designed so that the maximum bending stress remains the same at every section along its length. This is achieved by varying the cross-section in proportion to the bending moment, so the beam is equally stressed throughout.
Why the others are incorrect:
- a) Bending moment is not necessarily the same throughout the beam; it generally varies with loading and support conditions.
- b) Deflection being same throughout the length is not the definition of uniform strength.
- d) Shear stress being uniform throughout the beam is also not the criterion for a beam of uniform strength; the concept refers to bending stress, not shear stress.
Drilling is an example of -
A)
Simple cutting
B)
Uniform cutting
C)
Orthogonal cutting
D)
Oblique cutting
The cutting edges of a drill are inclined to the cutting direction, making drilling an oblique-cutting process.
Which of the following device is mostly associated with automation?
A)
NC machine
B)
Flexible manufacturing
C)
Computer graphics workstation
D)
Robots
Correct answer: D. Robots is the option that matches the standard principle or definition asked.
Product layout is employed for -
A)
Batch production
B)
Continuous production
C)
Effective utilisation of machine
D)
Mass production
Correct answer: D. Mass production is the option that matches the standard principle or definition asked.