Sonographic Physics Chapter 8 Part 2

This increases the efficiency of sound transmitted into and out of the body

• Gel

• PZT

• Backing layer

• Matching layer

This helps eliminate the air between the probe and the skin

• Outer case

• Filler

• Matching layer

• Gel

If the propagation speed is slow, what happens to the PZT when it vibrates?

• Higher frequency

• Lower frequency

• Loud noise

• Soft noise

If the propagation speed is fast, what will happen to the PZT when it vibrates?

• Higher frequency

• Lower frequency

• Loud noise

• Soft noise

What is the propagation speed of the PZT?

• 2000-4000 m/s

• 4000-6000 m/s

• 6000-8000 m/s

• 8000-10,000 m/s

True or False

Frequency produced by a PZT crystal depends on

1. 1. The speed of sound in the PZT

   1. 2. The thinness of the PZT

• True

• False

Answer explanation

the THICKNESS of the PZT

Thick crystals don't vibrate as fast as

• thin crystals

• high frequencies

• low frequencies

Thick crystals produce

• thin crystals

• low frequencies

• high frequencies

The thickness of the PZT is ___ wavelength of desired frequency

• 1/4

• 1/2

• 1/8

• 1/3

A thicker bevel produces a ___ frequency

• lower

• higher

• smaller

• larger