Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

In order to reverse the direction of rotation of a 3-phase induction motor

A. Motor should eb replaced
B. Power factor should be changed
C. Supply voltage should be cut off in one phase
D. Any two phases should be interchanged
E. All the three phases should be interchanged
Answer» E. All the three phases should be interchanged
2.

Gerber line for failure criteria is in the form of a

A. parabola
B. Increasing the diameter of threaded portion
C. straight line with negative slope
D. straight line with positive slope
E. hyperbola
Answer» B. Increasing the diameter of threaded portion
3.

If water in closed pipe freezes, the pipe will

A. Rupture in a plane inclined at 45 degree to the longitudinal axis of the pipe
B. Rupture along a line running longitudinally along the pipe
C. Rupture along a plane perpendicular to the axis of pipe
D. Rupture zig-zag along the length
E. Rupture along weakest circumferential section
Answer» C. Rupture along a plane perpendicular to the axis of pipe
4.

While designing a shaft pulley and key for a system

A. Shaft is the weakest member
B. Pulley is the weakest member
C. Key is the weakest member
D. All are designed for equal strength
E. None of the above
Answer» D. All are designed for equal strength
5.

In case of steels, as the percentage of carbon content increases

A. Elongation increases
B. Chrome steel
C. Hardness decreases
D. Tensile strength increases
E. Weldability increases
Answer» E. Weldability increases
6.

The approximate value of allowable stress for carbon steel under static loading (in kg/cm2) is

A. 500-1000
B. 10000-15000
C. 4000-7500
D. 20000-25000
E. 15000-20000
Answer» D. 20000-25000
7.

Bush bearings

A. Phosphor bronze
B. Aluminium bronze
C. Mild steel
D. White metal alloys
E. None of the above
Answer» E. None of the above
8.

A solderberg line for ductile material gives upper limit for

A. Increasing the diameter of threaded portion
B. alternating tensile stress
C. alternating compressive stress
D. any combination of mean and alternating stresses
E. mean stress
Answer» E. mean stress
9.

The basic hole is one which has

A. Upper deviation as zero
B. Lower deviation as zero
C. Lower as well as upper deviation within narrow limits
D. Lower as well as upper deviation are zero
E. None of the above
Answer» C. Lower as well as upper deviation within narrow limits
10.

At the first critical speed a shaft will

A. Remain straight
B. Bend to the simplest shape possible
C. Bend to maximum permissible depth
D. Bend to the convex form
E. Vibrate producing audible sound
Answer» C. Bend to maximum permissible depth
11.

Which of the following joint is used for pipes carrying water under low pressures?

A. Socket joint
B. Increasing the diameter of threaded portion
C. Expansion joint
D. Adhesive joint
E. Welded joint
Answer» B. Increasing the diameter of threaded portion
12.

For a bearing which of the following is maximum?

A. Minimum life
B. Average life
C. Median life
D. (A), (B) and (C) above are identical
E. Increasing the diameter of threaded portion
Answer» D. (A), (B) and (C) above are identical
13.

When properly made, a butt weld has the strength equal to

A. Double the tensile strength of plates
B. Half the tensile strength of plates
C. Half the compressive strength of plates
D. The strength of the welded plates
E. Double the compressive strength of plates
Answer» E. Double the compressive strength of plates
14.

In case of worm and worm-wheel the maximum efficiency is obtained when

A. Worm is driver
B. Worm wheel is driver
C. Either of the worm or worm wheel is a driver
D. Depends on other factors
E. None of the above
Answer» D. Depends on other factors
15.

Auto frettage is a

A. extra cover provided on seamless pipes to increase their hoop stress
B. a means of inducing favourable residual stresses in pressure vessels
C. Increasing the diameter of threaded portion
D. a heat treatment for pressure vessels subjected to low temperatures
E. surface coating process
Answer» C. Increasing the diameter of threaded portion
16.

Which of the following formula for columns takes into account any initial crookedness of the column and imperfectness of axial loading?

A. Secant formula
B. Increasing the diameter of threaded portion
C. Euler's formula
D. Rankiness formula
E. Perry Robertson formula
Answer» B. Increasing the diameter of threaded portion
17.

Self-tapping screws are generally used in

A. Shear metal work
B. Machine tools
C. Automobiles
D. Aeroplanes
E. None of the above
Answer» B. Machine tools
18.

In a standard coarse thread bolt the stress concentration is maximum at

A. Top surface
B. Pitch circle
C. Root
D. All over the surface
E. Flank
Answer» D. All over the surface
19.

If a machine member is loaded in such a way that the three principal stresses at a point are 600 kg/cm2 tension, 800 kg/cm2 compression and zero. The maximum shear stress at the point will be

A. 400 kg/cm2
B. 800 kg/cm2
C. 600 kg/cm2
D. 1000 kg/cm2
E. 200 kg/cm2
Answer» B. 800 kg/cm2
20.

In a Vee belt the angle between the sides is

A. 30?
B. 20?
C. 60?
D. 40?
E. 10?
Answer» E. 10?
21.

Wing screws are used where

A. tight grip is essential
B. frequently manual locking and unlocking is necessary
C. stress reversal is severe
D. high torque is needed for tightening
E. Increasing the diameter of threaded portion
Answer» C. stress reversal is severe
22.

Which of the following is not the result of cold work?

A. Increased tensile strength
B. Increasing the diameter of threaded portion
C. Reduced ductility
D. Reduced shock resistance
E. Reduced hardness
Answer» F.
23.

All of the following statements are false except

A. The pitch of a sinle threaded screw is equal to the lead
B. In a flange coupling, the bolts are subjected to compressive stress
C. Oldham coupling is used for connecting piston rod of a steam engine to the cross head
D. The resilience of a bolt may be increased by decreasing its shank diameter
E. Increasing the diameter of threaded portion
Answer» B. In a flange coupling, the bolts are subjected to compressive stress
24.

In V-belt drive the belt touches

A. At bottom
B. At sides only
C. Both at bottom as well as sides
D. Anywhere
E. None of the above
Answer» F.
25.

The basic design stress adopted for the design of light gauge steel members is

A. the stress at limit of proportionality
B. the yield stress divided by 1.85
C. the yied stress
D. the permissible stress
E. Increasing the diameter of threaded portion
Answer» C. the yied stress
26.

In watches and gramophones, which spring is most commonly used

A. Flat spiral spring
B. torsion helical spring
C. conical helical spring
D. none of the above
E. Cast steel
Answer» B. torsion helical spring
27.

The edges of boiler plates for fullering and caulking are bevelled at an angle of

A. 60?
B. 45?
C. 70?
D. 30?
E. 80?
Answer» F.
28.

A taper bearing has

A. Tapered roller
B. Tapered inner race
C. Tapered shaft
D. Tapered cage
E. Tapered outer race
Answer» B. Tapered inner race
29.

Regenerative braking is used on

A. Earth moving machines
B. Heavy duty trucks
C. Electric locomotives
D. Diesel locomotives
E. Steam locomotives
Answer» D. Diesel locomotives
30.

While designing for screw threads care should be taken to provide adequate length of engagement for the screw and nut threads so as to prevent failure of threads in

A. Tension
B. Compression
C. Torque
D. Shear
E. None of the above
Answer» E. None of the above
31.

The plastic section modulus is

A. the ratio of plastic moment capacity of a section to the yield moment
B. Increasing the diameter of threaded portion
C. the ratio of moment of inertia to radius of gyration
D. the ratio of plastic moment capacity to the field stress
E. area multiplied by the radius of gyration
Answer» B. Increasing the diameter of threaded portion
32.

Stub teeth are provided on gears

A. For high velocity ratios
B. Low noise
C. Large power transmission
D. Improved capability to withstand shock and vibrations
E. All of the above
Answer» E. All of the above
33.

Ball bearing type screws

A. Sliding friction is replaced by rolling friction
B. There is a ball bearing provided on the screwed shafts
C. Are self-locking
D. Friction is more
E. Have load bearing capacity for more than vee threads
Answer» B. There is a ball bearing provided on the screwed shafts
34.

The piston of a internal combustion engine is subjected to

A. fully reversed stresses
B. repeated stresses
C. Increasing the diameter of threaded portion
D. partly repeated stresses
E. partly reversed stresses
Answer» F.
35.

In a central heating system, the seamless copper tubing used has an inside diameter of 20 mm and a wall thickness of 0.6 mm. For a maximum pressure of 1750 Kpa, when allowable stress is 225 Mpa, the safety factor will be

A. 7.7
B. 9.9
C. 3.3
D. 5.5
E. Increasing the diameter of threaded portion
Answer» B. 9.9
36.

In a stone jaw crusher the main crank bearings are

A. Taper roller bearings
B. Roller bearings
C. Ball bearings
D. Double row ball bearings
E. Self-aligning ball bearings
Answer» C. Ball bearings
37.

The edge of the plates for boilers and tanks are usually bevelled at an angle of 80?

A. To reduce stress concentration
B. For safety
C. To facilitate joining
D. For fullering and caulking
E. None of the above
Answer» E. None of the above
38.

A self-socking screw is one which

A. Has locking arrangement
B. Has a hole drilled through for inserting locking pin
C. Has coefficient of friction equal to or greater than the tangent of the load angle
D. Has fine pitch screw threads
E. None of the above
Answer» D. Has fine pitch screw threads
39.

Lewis equation in ears is used to evaluate

A. Tensile stress in bending
B. Compressive stress in bending
C. Creep stress
D. Endurance limit
E. Shear stress on flank
Answer» C. Creep stress
40.

Maximum gear ratio can be expected in case of

A. Spur gears
B. Worm and worm wheel
C. Helical gears
D. Straight bevel gears
E. Double helical gears
Answer» C. Helical gears
41.

Neglecting bending, for a parallel load on a fillet weld of equal legs the plane of maximum shear occurs at

A. 45?
B. 15?
C. 60?
D. 30?
E. 22
Answer» B. 15?
42.

Which pair of gears usually has high friction losses?

A. All have equal frictional loss
B. Spur gears
C. Bevel gears
D. Helical gears
E. Worm and worm wheel
Answer» F.
43.

In the case of ball bearings the contacting areas between balls and running tracks are

A. circular
B. parabolic
C. elliptical
D. none of the above
E. Cast steel
Answer» D. none of the above
44.

The value of yield stress for structural steel is about

A. Increasing the diameter of threaded portion
B. 3600 kg/cm2
C. 1600 kg/cm2
D. 4600 kg/cm2
E. 2600 kg/cm2
Answer» F.
45.

Poisson's ratio for rubber is taken as

A. 0.1
B. 1
C. Zero
D. 2
E. 0.5
Answer» F.
46.

The maximum size of the fillet weld that can be used is

A. Increasing the diameter of threaded portion
B. 3 mm
C. 7 mm
D. 1 mm
E. 5 mm
Answer» C. 7 mm
47.

In plastic analysis, the shape factor of a triangular section is

A. 1.15
B. Increasing the diameter of threaded portion
C. 2.34
D. 1.5
E. 1.85
Answer» D. 1.5
48.

The diameter of rivets for 20 mm thick plates would be

A. 10 mm
B. 20 mm
C. 15 mm
D. 40 mm
E. 30 mm
Answer» E. 30 mm
49.

The plastic design of a structure based on which of the following is always safe?

A. Mechanism method of analysis
B. Statistical method of plastic analysis
C. Upper bound theorem of plastic analysis
D. All of the above
E. Increasing the diameter of threaded portion
Answer» C. Upper bound theorem of plastic analysis
50.

The plastic design of steel structures which is based on upper bound theorem is

A. safe, unsafe
B. Increasing the diameter of threaded portion
C. unsafe, unsafe
D. safe, safe
E. unsafe, safe
Answer» F.