Lecture 14

Question 1

Piezoelectricity involves a

Answer 1

Element

Question 2

Sound beam will naturally come to a

Answer 2

Focus

Question 3

Opposite of natural focus

Answer 3

Electronic focus

Question 4

Near zone aka

Answer 4

Frensel zone or near field

Question 5

The near zone is the region extending

Answer 5

From the transducer to the minimum beam width

Question 6

Beam width decreases w/ increasing _______ this is called _______

Answer 6

Distance from the transducer

Convergence

Question 7

Far zone aka

Answer 7

Fraunhofer zone

Far field

Question 8

The far zone is the region

Answer 8

That lies beyond a distance of one near zone length

Question 9

Beam width increases in far zone w/ ___________ this is called ______

Answer 9

Increasing distance from the transducer

Beam divergence

Question 10

Aperature meaning ______

Answer 10

Opening

Question 11

Aperature is

Answer 11

The element size (width) for a single disk transducer/ the width of group of elements

Question 12

Beam profile=

Answer 12

Width - wb

Question 13

Beam width changes w/

Answer 13

Depth

Question 14

Beam width affects ______ of signal at that depth

Answer 14

Resolution

Question 15

Beam width also affext the _______of the sound beam at that depth

Answer 15

Intensity

Question 16

Intensity is not ____ within the beam

Answer 16

Uniform

Question 17

Power is _______ within the the beam

Answer 17

Uniform

Question 18

At the focus

Wb=

Answer 18

0.5 the aperture size

Question 19

Width of a disk transducer element is

Answer 19

1.5mm

Question 20

NZL is determined by (2)

Answer 20

Size of the element(s) (aperture)

Operating frequency

Question 21

I aperature increases NZL _____

Answer 21

Increases

Question 22

If operating frequency increases then NZL ______

Answer 22

Increases

Question 23

T/f there is no far zone length

Answer 23

T

Question 24

Natural focus is at end of

Answer 24

Near zone

Question 25

At double the NZL width =

Answer 25

Element width/diameter

Question 26

Focal length is

Answer 26

Distance to the focus

Same length of near zone length

Question 27

Higher frequency transducers tend to hac _____ footprints

Answer 27

Smaller

Question 28

Smallest beam width has the strongest _______ therefore _____

Answer 28

Intensity

Will pick up more signals

Question 29

Better _______ is given with smaller beam width

Answer 29

Resolution

Question 30

Improved focusing resolution only occurs in the _______

Answer 30

Near zone

Question 31

Beam width is decreased in the _______ and widens in the _________

Answer 31

Focal region

Region beyond

Question 32

Focusing can be accomlished by (2)

Answer 32

Curved lens/ element

Phasing

Question 33

An increase in curve of element results in

Answer 33

Closer focus

Question 34

Curved element is a type of _______ focusing

Answer 34

Mechanical