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.

51.

Film contrast is the inherent ability of a film to show for a given change in film exposure.

A. No appreciable change in density
B. Graininess
C. A difference in density
D. No graininess
Answer» D. No graininess
52.

A magnetic particle build-up from a discontinuity is strongest when the discontinuity is oriented:

A. 180o to the magnetic field
B. 45o to the magnetic field
C. 90o to the magnetic field
D. 90o to the current flow
Answer» D. 90o to the current flow
53.

A weld discontinuity which consists of unmelted joint surfaces at the root, and which may be caused by poor fit- up, is called:

A. Hot short cracking
B. A slag inclusion
C. Incomplete penetration
D. Burn through
Answer» D. Burn through
54.

A weld discontinuity which consists of unmelted joint surfaces at the root, and which may be caused by poor fit-up, is called:

A. Hot short cracking
B. A slag inclusion
C. Incomplete penetration
D. Burn through
Answer» D. Burn through
55.

A depression at the edge of a weld where the base metal has been melted during welding is called:

A. Burn through
B. Undercut
C. Root concavity
D. Root convexity
Answer» C. Root concavity
56.

What action is necessary if the penetrant is inadvertently allowed to dry on the test piece?

A. Repeat the test, beginning with the pre-cleaning operation
B. Re-wet the penetrant, begin dwell time again and continue
C. Clean the penetrant off the surface and develop normally
D. Clean the penetrant off the surface, wait 5 minutes and develop normally
Answer» B. Re-wet the penetrant, begin dwell time again and continue
57.

According to ASTM E709-95 and API, the UV intensity measured at a minimum of 38 cm (15 inches) at least shall not be less than:

A. 700 W/cm2
B. 800 W/cm2
C. 900 W/cm2
D. 1000 W/cm2
Answer» E.
58.

According to ASTM E709-95 and API, the thickness of non conductive coatings will not exceed:

A. 1-10 mm
B. 2-5 mm
C. 0.02-0.05 mm
D. 0.001-0.004 mm
Answer» D. 0.001-0.004 mm
59.

According to API, the acceptable particle concentration of wet particle solution for fluorescent particles is:

A. 0.1 to 0.4 mL by volume
B. 0.1 to 0.5 mL by volume
C. 0.1 to 0.6 mL by volume
D. 0.1 to 0.7 mL by volume
Answer» B. 0.1 to 0.5 mL by volume
60.

According to ASTM E709-95 in using prod technique on a 50 mm thickness plate with a prod spacing of 101 mm (4 inches), current shall be selected in the following range:

A. 300-450A
B. 400-500 A
C. 500-625A
D. 550-700 A
Answer» B. 400-500 A
61.

The density of the radiograph through the weld area is 3.2 while the density in the base metal is 2.9. This would probably indicate:

A. Too high a kV was used
B. Too low a kV was used
C. There is excessive weld reinforcement
D. Weld underfill
Answer» E.
62.

According to ASTM E709-95 powder shall be applied upon the part to be tested in such a manner that:

A. A light uniform coating is formed
B. In excess coating
C. All of the above
D. None of the above
Answer» B. In excess coating
63.

Which of the following describes the shape of particles used for dry magnetic particle testing?

A. Spherical
B. Angular
C. Elongated
D. Mixture of elongated and globular
Answer» E.
64.

A radiographic exposure with 3700 GBq (100 Ci) source of Ir-192 using source to film distance of 60 cm results in a radiation intensity of 0.12 Gy/h (11.8 R/h) and a radiographic density of 2.5. The intensity of radiation needed to obtain the same density when the source to film distance is changed to120 cm is:

A. 0.472 Gy/h (47.2R/h)
B. 0.118 Gy/h (11.8 R/h)
C. 0.029 Gy/h (2.9 R/h)
D. 0.236 Gy/h (23.6 R/h)
Answer» D. 0.236 Gy/h (23.6 R/h)
65.

According to ASTM E709-95 and API, the temperature of the dry particles can be usable up to:

A. 38 C
B. 2000 C
C. 49 C
D. 315 C
Answer» E.
66.

What is the longest period of time which should elapse between complete changes of developer solution?

A. 1 week
B. 2 weeks
C. 1 month
D. 3 months
Answer» E.
67.

A low density image of the letter B on a radiographic film would probably be caused by:

A. Under exposure
B. Excessive exposure
C. Excessive backscatter
D. Insufficient backscatter
Answer» D. Insufficient backscatter
68.

According to ASTM E709-95 and API, when fluorescent particles are used, the UV bulb shall warm up prior to use for at least:

A. 1 minute
B. 2 minutes
C. 3 minutes
D. 5 minutes
Answer» E.
69.

According to ASTM E709-95 in using prods having a spacing of 19 mm (3/4 inches) and above, the magnetizing current shall be:

A. From 90 to 110 A/25 mm (1 inch)
B. From 100 to 125 A/25 mm (1 inch)
C. From 90 to 120 A/ 25 mm (1 inch)
D. From 100 to 200 A/25 mm (1 inch)
Answer» C. From 90 to 120 A/ 25 mm (1 inch)
70.

According to ASTM E709-95 before turning off current and examination, dry powder in excess shall be:

A. Removed by a dry-air current
B. Kept in place
C. All of the above
D. None of the above
Answer» E.
71.

Which type of penetrant process would be best suited to the detection of wide, shallow discontinuities?

A. Solvent removable
B. Water washable
C. Post emulsifiable
D. Fluorescent
Answer» D. Fluorescent
72.

A magnetic particle indication is sharp and very fine; this suggests that the discontinuity is:

A. Subsurface seam
B. A shallow, tight surface crack
C. Porosity
D. A deep crack
Answer» C. Porosity
73.

If the radiation intensity is 5 Gy/h (500 R/h) at a distance of 152.4 cm (5 feet) from a source, what is the intensity at 1524 cm (50 feet)?

A. 0.5 Gy/h (50 R/h)
B. 1.0 Gy/h (100 R/h)
C. 0.1 Gy/h (10R/h)
D. 0.05 Gy/h (5 R/h)
Answer» E.
74.

If the required exposure time for a 1850 GBq (50 curie) Ir-192 source is 4 minutes, what exposure time would be required for 925 GBq (25 curie) source:

A. 4 minutes
B. 8 minutes
C. 2 minutes
D. 16 minutes
Answer» C. 2 minutes
75.

If the required exposure time for a 2220 GBq (60 curie) Ir-192 source is 2 minutes, what exposure time would be required at 1110 GBq (30 curie) source:

A. 2/3 minutes
B. 60 minutes
C. 2 minutes
D. 4 minutes
Answer» E.
76.

According to ASTM E709-95 when applying fluorescent magnetic particles technique, the operator shall be in darkness area at least......................prior to examination:

A. 2 min
B. 3 min
C. 4 min
D. 5 min
Answer» C. 4 min
77.

If the radiation intensity is 1 Gy/h (100 R/h) at a distance of 152.4 cm (5 feet) from a source, what is the intensity at 610 cm (20 feet)?

A. 0.0625 Gy/h (6.25 R/h)
B. 0.25 Gy/h (25 R/h)
C. 16 Gy/h (1600 R/h)
D. 4 Gy/h (400 R/h)
Answer» B. 0.25 Gy/h (25 R/h)
78.

According to ASTM E709-95 when fluorescent particles are used, the bulb shall be warmed up prior to use for at least:

A. 1 min
B. 2 min
C. 3 min
D. 4 min
Answer» E.
79.

According to ASTM E709-95 when fluorescent particles are used, the UV light intensity shall be above:

A. 700 W/cm2
B. 800 W/cm2
C. 900 W/cm2
D. 1000 W/cm2
Answer» E.
80.

If the required X ray exposure time for a 225 kV, 5 mA exposure is 3 minutes, approximately what exposure time would be required at 10 mA?

A. 1/2 minute
B. 1 minute
C. 1.5 minutes
D. 3 minutes
Answer» D. 3 minutes
81.

If the required X ray exposure time for a 150 kV, 5 mA exposure is 2 minutes, approximately what exposure time would be required at 10 mA?

A. 1/2 minute
B. 1 minute
C. 2 minutes
D. 4 minutes
Answer» C. 2 minutes
82.

Which of the following techniques would probably reduce the amount of back scattered radiation reaching the film during a radiographic exposure?

A. Using a finer grained film
B. Backing the cassette with a sheet of lead
C. Removing lead screens
D. All of the above
Answer» C. Removing lead screens
83.

For a 7.6 cm (3 inches) diameter bar how much current is needed to magnetize the bar for the detection of longitudinal discontinuities:

A. 5500 amperes
B. 16500 amperes
C. 1000 amperes
D. 3000 amperes
Answer» E.
84.

Which of the following is an advantage of gamma ray over X ray sources for radiography?

A. Portability
B. No external power supply needed
C. Ruggedness
D. All of the above
Answer» E.
85.

Gamma ray or high voltage X ray radiography, using film without lead screens, is likely to result in:

A. Mottling of the film
B. Increased geometric unsharpness
C. No apparent difference, but increased exposure time
D. No apparent difference, but decreased exposure time
Answer» B. Increased geometric unsharpness
86.

When a longitudinal wave is incident upon an inclined interface and is refracted at ninety degrees, the angle of the incident longitudinal wave is called:

A. The Snell constant
B. The Snell angle
C. The mode conversion constant
D. The first critical angle
Answer» E.
87.

Which of the following is an advantage of X ray over gamma ray sources for radiography?

A. Safety
B. Variable radiation intensity
C. Variable radiation energy
D. All of the above
Answer» E.
88.

Natural discontinuities comparable in size to the penetrameter holes shown on a radiograph may not be detected because:

A. Natural discontinuities may contain less dense material than the penetrameter holes
B. Natural discontinuities may be thicker than the penetrameter holes
C. Natural discontinuities do not necessarily have as sharp edges as the penetrameter holes
D. All of the above
Answer» D. All of the above
89.

An increase in gain of how many decibels corresponds to a 5:1 increase in flaw echo amplitude?

A. 10
B. 14
C. 6
D. 20
Answer» C. 6
90.

The degree of concentration of the radioactive material in gamma ray sources is referred to as the:

A. Atomic weight of the source
B. Half-life of the source
C. Quality of the source
D. Specific activity of the source
Answer» B. Half-life of the source
91.

For gamma ray sources, radiographic intensity is proportional to source activity in gigabecquerels or curies for:

A. All sources
B. Large sources
C. Small sources
D. None of the above
Answer» B. Large sources
92.

Radiography of tubular sections using a double wall, double viewing technique is mainly applicable to sections:

A. Over 38 mm in diameter
B. 88 mm in diameter or less
C. 125 mm in diameter and less
D. Under 25 mm in diameter
Answer» C. 125 mm in diameter and less
93.

Most scattered radiation which adversely affects the radiographic image quality originates:

A. From floors and walls adjacent to the test piece
B. From other nearby objects
C. From the test piece itself
D. From the lead intensifying screens
Answer» B. From other nearby objects
94.

How many ampere-turns are required to magnetize a part that is 40.6 cm (16 inches) long and 5 cm (2 inches) in diameter?

A. 9000 ampere-turns
B. 5625 ampere-turns
C. 2812 ampere-turns
D. None of the above
Answer» C. 2812 ampere-turns
95.

What is the magnetic field strength at the surface of a 25 mm diameter bar as compared to that at the surface of a 50 mm diameter bar, each carrying 1000 amps of current?

A. Twice
B. One half
C. One quarter
D. Four times
Answer» B. One half
96.

What is the magnetic field strength at the surface of a 25mm diameter bar as compared to that at the surface of a 50mm diameter bar, each carrying 1000 amps of current?

A. Twice
B. One half
C. One quarter
D. Four times
Answer» B. One half
97.

The amount of amperage used for magnetic particle inspection using the prod method is determined from the:

A. Type of material
B. Distance between the prods
C. Diameter of the part
D. Total length of the part
Answer» C. Diameter of the part
98.

What is the magnetic field strength at the surface of a 100 mm diameter bar as compared to that at the surface of a 50 mm diameter bar, each carrying 1000 amps of current?

A. Twice
B. One half
C. One quarter
D. Four times
Answer» C. One quarter
99.

The most effective NDT method for locating surface cracks in ferromagnetic materials is:

A. Ultrasonic testing
B. Radiographic testing
C. Magnetic particle testing
D. Liquid penetrant testing
Answer» D. Liquid penetrant testing
100.

A change in which the following parameters would require a new X ray exposure chart?

A. kV
B. X ray machine
C. Test piece thickness
D. All of the above
Answer» C. Test piece thickness