Questions for Ultrasonic Testing – General

Questions for Ultrasonic Testing – General

1) The distance from a given point the on an ultrasonic wave to the next corresponding point is referred to as:

(a)       frequency

(b)       wavelength

(c)       velocity

(d)       pulse length

2) In general, following activity occur at interface:

(a)     reflection

(b)       refraction

(c)     transmission

(d)       all of the above

3) In resonance testing, indication may be obtained either at the fundamental resonant frequency or at ……………… which are multiples of the fundamental frequency.

(a) multiple frequency

(b)       harmonics

(c)       antinodes

(d)       nodes

4) A transducer has a near field in water of 96 mm. when used in contact testing (straight beam) on steel the near zone will near about:

(a)       47 mm

(b)       35 mm

(c)       30 mm

(d)       24 mm

5) Reference standards containing a series of flat bottom holes of the same diameter at different depths in each block are called?

(a)       Area-amplitude blocks

(b)       Distance-amplitude blocks

(c)       IIW blocks

(d)       Sizing blocks

6) Scattering of the ultrasound is a result of:

(a)       frequency

(b)       sound velocity

(c)       angulations

(d)       material grain size

7) A PZT transducer loses its piezoelectric property if:

(a)       immersed in water

(b)       used on forging that has not been de-magnetized

(c)       used on a surface whose temperature above 140°C

(d)       heated above its curie point

8) A rectangular angle probe frequency 4MHz, size 8 x 9 mm, what will have its half angle of divergence in steel along major axis ( where K = 0.5)

(a)       nearly 2.58°

(b)       nearly 5.16°

(c)       nearly 2.7°

(d)       nearly 3.0°

9) Wave use in ultrasonic testing of the materials are ………………in nature:

(a)       mechanical

(b)       magnetic

(c)       electromagnetic

(d)       harmonious

10) The number of cycle of vibration per second is known as:

a) period

b) wavelength

c) frequency

d) hypotenuse

11) Particle motion in a longitudinal wave is:

(a)      parallel to the direction of wave propagations

(b)      perpendicular to the direction of wave propagations

(c)      retrograde

(d)      counter clockwise ellipse

12) The fundamental frequency of a piezoelectric crystal used in ultrasonic is a function of:

a) its thickness

b) the velocity of sound in the crystal material

c) both a and b

d) none of the above

13) A longitudinal wave generating transducer will have a given near field in steel. If in water the near field for this probe will be:

a) the same distance

b) about half as long

c) about 1/4 as long

d) about 4 times as long

14)      which of the following is the Snell’s law

(a) sin i/sin r = Vi / Vr

(b) sin i/sin r = Vr / Vi

(c) sin i/sin r = Vi x Vr

(d) none of the above

15)      Another name for Rayleigh wave is:

(a) longitudinal wave

(b) transverse wave

(c) surface wave

(d) plate wave

16)      The ultrasonic attenuation due to the following reason

(a) absorption

(b) scattering

(c) divergence

(d) all of the above

17)      Transverse wave can travel through

a) solid

b) solid, liquid and gas

c) solid, liquid, gas and vacuum

d) all of the above

18)      Compression wave can travel through

a) solid

b) solid, liquid and gas

c) solid, liquid, gas and vacuum

d) all of the above

19)      The refracted wave will travel at angle

a) same as incident

b) same as reflected

c) depend on velocity in material

d) none of the above

20)      The divergence of an ultrasonic beam is dependent on:

(a)     Transducer wavelength and diameter

(b)     Test specimen density

(c)      The sound wave’s angle of incidence

(d)     The degree of damping of the ultrasonic transducer

21)      An instrument display in which the horizontal base line represents elapsed time and the vertical deflection represents signal amplitudes is called:

(a)      A scan

(b)      B scan

(c)     C scan

(d)     A time line display

22)      As ultrasonic frequency increases:

(a)      Wavelength increases

(b)      Wavelength decreases

(c)      Sound velocity increases

(d)      Sound velocity decreases

23)      Resolving power of a transducer is directly proportional to it’s:

(a)      Wavelength

(b)      Crystal thickness

(c)      Bandwidth

(d)      Q

24)      For an ultrasonic beam with normal incidence the transmission is given by:

(a)      [(Z1+Z2)2]/ [(Z1-Z2)2]

(b)      (Z1+Z2)/ (Z1-Z2)

(c)      [(4) (Z1) (Z2)]/ [(Z1+Z2)2]

(d)      [(Z1-Z2)2]/ [Z1+Z2)2]

25)      When a longitudinal wave is incident upon an inclined interface and is refracted at 90 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

26)      When the motion of the particles of a medium is transverse to the direction of propagation, the wave being transmitted is called a:

(a)      Longitudinal wave

(b)       Shear wave

(c)       Surface wave

(d)       Lamb wave

27)      Sound beam intensity is irregular/ unexpected in the area called:

(a)       The near field

(b)       The far field

(c)       The beam spread

(d)       The delay line

28)      A more highly damped transducer crystal results in:

(a)       Better resolution

(b)       Better sensitivity

(c)       Lower sensitivity

(d)       Poorer resolution

29)      Which of the following search units would contain the thinnest quartz crystal?

(a)       A 100 KHz search unit

(b)       A 5000 Hz search unit

(c)       A 15 MHz search unit

(d)       A 25 MHz search unit

30)      The ability to separate echoes from reflectors close together in depth is called:

(a)       Resolution

(b)       Attenuation

(c)       Accuracy

(d)      Sensitivity

31) Greater depth of penetration in coarse grain material may be achieved

(a)       more sweep delay

(b)       higher frequency

(c)       less sweep delay

(d)       lower frequency

32) Lower frequency transducer produce:

(a)       deeper penetration, greater attenuation and less beam spread

(b)       deeper penetration, less attenuation and greater beam spread

(c)       greater beam spread but higher sensitivity and resolution

(d)      less beam spread but lower sensitivity and resolution

33) An ultrasonic display which shows a cross section of the test piece that is:

(a)       A scan

(b)       B scan

(c)       C scan

(d)       orthogonal view

34) Choice of ultrasonic test frequency depends upon which of the following?

(a)       surface condition

(b)       minimum size discontinuity to be detected

(c)     level of grain noise

(d)     All of the above

35) How many decibels of attenuation correspond to an ultrasonic signal loss from 100% to 25% on full screen hight?

(a)       6

(b)       10

(c)       12

(d)       14

36) An increase in gain, how many decibels corresponds to 5:1 increase in flaw echo amplitude?

(a)       20

(b)       14

(c)       10

(d)     6

37) Which of the following is an advantage of contact testing over immersion?

(a)       ability to maintain uniform coupling on the rough surface

(b)       longer dead time near the front surface of the test piece

(c)       ease of field use

(d)       ability to continuously vary incident wave angle during test

38) Which of the following is a disadvantage of contact testing?

(a)       ability to maintain uniform coupling on the rough surface

(b)       longer dead time near the front surface of the test piece

(c)     ease of field use

(d)      None of the above

39)      A typical application for a through transmission technique is:

(a)      flaw depth sizing

(b)      flaw depth location

(c)      thickness gauging

(d)      bond / unbond testing

40)      Which probe has highest near field distance for same medium?

(a)      25 MHz, 5 mm dia

(b)       10 MHz, 5 mm dia

(c)       5 MHz, 5 mm dia

(d)       all have same