Chapter 9

Question 1

Focus or focal point

Answer 1

the location where the beam is the narrowest

Question 2

near zone near field or fresnel zone

Answer 2

the region from the transducer to the focus

Question 3

focal length focal depth or near zone length

Answer 3

distance from the transducer to the focus

Question 4

far zone far field or Fraunhofer zone

Answer 4

is the region that starts at the focus and extends deeper

Question 5

focal zone

Answer 5

around the focus where the beam is relatively narrow

Question 6

Synonym for focus

Answer 6

focal point, the end of the near zone, the beginning of the far zone, or the middle of the focal zone

Question 7

Focal depth focal length near zone length

Answer 7

distance from the transducer to the narrowest part of the beam

Question 8

what are the two factors that determine focal depth

Answer 8

transducer diameter
frequency of the sound

Question 9

what is the rule of physics

Answer 9

higher frequency sound creates a deeper focus

Question 10

Beam divergence

Answer 10

the gradual spread of the ultrasound beam in the far feild

Question 11

two factors to determine beam divergence

Answer 11

transducer diameter and frequency of the sound

Question 12

V shape wave are known as spherical wave, diffraction patterns or

Answer 12

Huygens’ principle