Explore topic-wise MCQs in Mechanical Engineering.

This section includes 335 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.

301.

Which penetrant process is best suited to the detection of discontinuities in a test piece having threads and keyways?

A. Solvent removable
B. Water washable
C. Post emulsifiable
D. Fluorescent
Answer» C. Post emulsifiable
302.

Source-to-object distance, object-to-film distance, and source size are the three factors that control the of the radiograph.

A. Density
B. Exposure
C. Film size
D. Unsharpness
Answer» E.
303.

A dark crescent shaped spot, clearly in the base metal adjacent to a weld would probably be:

A. Burn through
B. Film crimp mark
C. A crack
D. A water spot on the film
Answer» C. A crack
304.

The range of the specimen thickness that can be adequately recorded on a radiograph is known as the of the radiograph.

A. Sensitivity
B. Latitude
C. Accuracy
D. Intensity
Answer» C. Accuracy
305.

Dyes which receive light at one wavelength and re-emit light of another wavelength are called:

A. L.E.Ds
B. Phosphorescent
C. Luminescent
D. Fluorescent
Answer» E.
306.

Why is it important to view the test piece shortly after developer application and periodically through the development time?

A. To make sure the developer dries evenly
B. To guard against pooling of developer in low areas
C. To avoid missing small flaw indications adjacent to areas of high bleed-out
D. To avoid missing transient indications against an otherwise clean background
Answer» D. To avoid missing transient indications against an otherwise clean background
307.

While performing a fluorescent water washable penetrant test, which of the following steps should be performed under black light?

A. Penetrant application
B. Excess penetrant removal
C. Emulsification
D. Developer application
Answer» C. Emulsification
308.

Which of the following is not (!) an advantage of a water washable fluorescent penetrant process?

A. Excess penetrant is easily removed with a water wash
B. It is well suited to testing large quantities of small parts
C. It is readily removed from shallow discontinuities
D. It has low cost, low processing time compared to the post emulsified penetrant process
Answer» D. It has low cost, low processing time compared to the post emulsified penetrant process
309.

The multi-film technique may be used when one radiograph film does not have enough to produce a satisfactory radiograph of a specimen.

A. Latitude
B. Definition
C. Graininess
D. Activity
Answer» B. Definition
310.

What is the preferred method of removing paint prior to performing a penetrant testing?

A. Sand blast
B. Chemical removers
C. Power wire brush
D. Shot blast
Answer» C. Power wire brush
311.

The fluorescent dyes used in the liquid penetrant testing process are most active when energised with black light of what wavelengths? ( stands for angstrom units)

A. 2.0 10-7m (2000 )
B. 2.5 10-7m (2500 )
C. 3.25 10-7m (3250 )
D. 3.65 10-7m (3650 )
Answer» E.
312.

A dark, sharply defined, straight line in the centre of the weld, and running parallel with the length of the weld should be interpreted as:

A. Porosity
B. Incomplete penetration
C. A slag inclusion
D. Lack of fusion
Answer» C. A slag inclusion
313.

A dark circle type indication appearing on a radiograph that is the result of the failure of a core support to completely melt is called:

A. A hot tear
B. A gas hole
C. An unfused chaplet
D. A spongy shrink
Answer» D. A spongy shrink
314.

The following precautions must be observed when removing the excess surface penetrant with a water wash method using a hose pipe:

A. The wash angle should be at 45o
B. A coarse droplet spray
C. Temperature of water 16 to 43oC
D. Pressure as low as possible not to exceed 50 psi
Answer» C. Temperature of water 16 to 43oC
315.

In performing a water content test of a lipophilic emulsifier per ASTM D-95, what solvent is used?

A. Naptha
B. Trichloroethane
C. Benzene
D. Xylene
Answer» E.
316.

Halogen content of penetrant materials is limited because of the possibility of stress corrosion cracking in which of the following materials?

A. High tensile steel
B. Austenitic stainless steel
C. Titanium alloys
D. All of the above
Answer» E.
317.

When performing a fluorescent penetrant examination, excess penetrant is normally removed:

A. By a hydrophilic scrubber
B. Under UV light
C. By solvent spray
D. By vapour degreasing
Answer» C. By solvent spray
318.

Which of the following developers requires the test piece to be dried prior to its application?

A. Water washable
B. Water suspendable
C. Non-aqueous suspendable
D. All of the above
Answer» D. All of the above
319.

Which of the following types of pre-cleaning processes may be used for liquid penetrant testing?

A. Wire brushing only
B. Detergent and water only
C. Vapour degreasing only
D. Any process that leaves the part clean and dry, does not harm the part and is
Answer» E.
320.

What is the minimum time considered necessary for dark adaptation of the eyes prior to evaluating the results of a fluorescent penetrant test?

A. 1 minute
B. 2 minutes
C. 5 minutes
D. 10 minutes
Answer» D. 10 minutes
321.

Dark rounded indications with rather smooth edges appear on the radiograph of casting made in sand mould. These indications would be interpreted as:

A. Slag inclusions
B. Misrun
C. Shrinkage
D. Gas holes
Answer» E.
322.

Which type of developer does not (!) provide a contrasting background against which to view penetrant indications?

A. Dry
B. Non-aqueous wet
C. Water soluble
D. Water suspendable
Answer» B. Non-aqueous wet
323.

Which of the following is normally prohibited as a method of removing excess penetrant when using the solvent removable penetrant process?

A. A water spray
B. A hydrophilic scrubber
C. A solvent spray
D. Clean with lint free towels moistened with solvent
Answer» D. Clean with lint free towels moistened with solvent
324.

Which of the following metals must be tested with low halogen sulphur free penetrant materials:

A. Copper, silver, gold
B. Nickel based alloys, certain stainless steel materials
C. Steel, iron, aluminium
D. Plastic, wood, paper
Answer» E.
325.

How will the excess surface penetrant be removed if a post emulsified penetrant was used:

A. Dip or spray emulsifier onto part
B. Wait correct dwell time
C. Water wash part observing correct recommended rules
D. Dry part and apply developer
Answer» D. Dry part and apply developer
326.

What is the proper technique for removal of excess penetrant from a part when using a water washable penetrant process?

A. Fine spray normal to the surface
B. Coarse spray normal to the surface
C. Fine spray at 45 degrees to the surface
D. Coarse spray at 45 degrees to the surface
Answer» E.
327.

During a visible, solvent removable penetrant test, complete penetrant removal is indicated by:

A. Absence of red indications on the test piece surface
B. Clean rinse water
C. Completion of the rinse cycle
D. Absence of red dye on the cleaning towels
Answer» E.
328.

Which of the following methods is not recommended for pre-cleaning prior to a liquid penetrant test:

A. Steam cleaning, etching, rust and paint removal
B. Solvent wipe, vapour degreasing, ultrasonic bath cleaning
C. Blasting, grinding, filing, honing, machining
D. All of the listed methods are not recommended
Answer» E.
329.

Excess penetrant removal is a two step process with which of the following penetrant methods?

A. Water washable
B. Post emulsifiable
C. Solvent removable
D. Liquid oxygen applications
Answer» C. Solvent removable
330.

Surface breaking porosity will show what type of relevant indications when a welded aluminium plate is tested with the liquid penetrant method:

A. Linear indications
B. Square indications
C. Triangular indications
D. Rounded indications
Answer» C. Triangular indications
331.

What is the likely result of incomplete removal of all excess penetrant from the test piece surface?

A. Formation of false indications
B. Formation of relevant indications
C. Exaggeration of the size of relevant indications
D. None of the above
Answer» B. Formation of relevant indications
332.

The reverse magnetising force necessary to remove a residual magnetic field from a test piece after it has been magnetically saturated is called:

A. Hysteresis
B. Coercive force
C. Demagnetising flux
D. Reverse saturation
Answer» C. Demagnetising flux
333.

Cracks, lack of penetration, lack of fusion which are surface breaking on a welded aluminium plate which has been liquid penetrant tested will show as:

A. Linear indications
B. Rounded indications
C. Square indications
D. Triangular indications
Answer» D. Triangular indications
334.

The time period during which penetrant remains on the surface of the test piece is called:

A. Dwell time
B. Soaking time
C. Fixing time
D. Development time
Answer» B. Soaking time
335.

Re-cycling of penetrant and rinse water is facilitated with which of the following emulsifier types?

A. Hydrophobic
B. Hydrophilic
C. Lipophilic
D. Hygroscopic
Answer» C. Lipophilic