Physics quiz

The angle between the direction of propagation and the boundary between two media is 90 degrees. What term describes the form of incidence of the wave?

Orthogonal

If the ___of two media are different and sound strikes a border between the media at 90 degrees incidence, then reflection will occur

impedances

One reflector is 5 times deeper than another. The time of flight of sound to the deeper structure is __ the time of flight of the shallower reflector

five times more than

You are purchasing a diagnostic ultrasound system. System X has axial resolution of 0.7mm whereas System D has an axial resolution of 0.4mm. Based on this information, which system will produce the better quality picture?

System D

True or False? The lower the numerical value of the longitudinal resolution, the worse the picture

False

True or False: One way the sonographer can alter the the axial resolution achieved during an exam is to adjust the maximum imaging depth

False

Which transducer has the best axial resolution?

2 cycles/pulse, 4MHz

Which component of the Ultrasound system is made of Lead Zirconate Titanate(PZT)?

active element

Which of the following lists orders the impedance from highest to lowest?

PZT, matching layer, gel, skin

What is the region from the transducer to the smallest cross-sectional area of a sound beam called?

fresnel zone

All of the following are true of the focus, EXCEPT:

it is at the start of the Fresnel zone

Huygen's principle is based on____

interference

Which of the following focusing techniques is different from the others?

phased

Which of the following techniques is consistent with variable or multi-focusing?

electronic

Which of the following terms means adjustable focusing or multi-focusing?

phased array

Density and propagation speed are:

inversely related

Wavelength depends on what two factors?

frequency & propagation speed

Which of the following biological tissues will have the slowest propagation speed of sound?

fat

Which of the following waves is within the audible range?

4000 Hz

In diagnostic imaging, frequency is determined by:

the source

Find the frequency if the period is 2 seconds.

0.5 Hz

The distance of one complete cycle is the:

wavelength

The intensity of a wave is:

proportional to the amplitude squared

___is the amount of complete cycles per second.

frequency

If frequency increases, each cycle (period) ________

decreases