Ultrasound physics Chapter 2 review
Which of the following bests describes ultrasound?
A mechanical vibration transmitted through a medium in the form of a wave
Sound is best described as _____.
A series of compressions and rarefactions
If waves are in-phase, their peaks occur
At the same tine
Which parameter of the medium has the most effect on the velocity of sound in that medium?
Bulk modulus of the medium
Units of distance is:
Cm, ft, miles
An area of high pressure and particle density on a pressure wave is referred to as a ____.
Compression
On a diagram of a waveform, the peak above the baseline represents
Compression
Positive amplitude of wave, an area of high pressure and particle density on a pressure wave is referred to as a:
Compression
The highest level of concentration of molecules in a wave is called
Compression
When waves of different frequencies interfere:
Constructive and destructive interference may occur
Interaction of echoes that causes reinforcement rather than cancellation is known as:
Constructive interference
What happens when two in-phase waves meet?
Constructive interference
When waves combine to form a single wave of less amplitude, it is called
Constructive interference
------------one compression and one rarefaction
Cycle
—— is concentration of mass within a volume.
Density
What happens when two out-of-phase waves meet?
Destructive interference
Sound waves carry ____ along their path.
Energy
Sound waves can go through a vacuum if the amplification is high enough.
False
Constructive interference has the effect of ____ the amplitude of a wave.
Increasing
Which of the following describes the sound wave phenomenon displayed in the image?
Interference
Units of density is:
Kg/cm3
The term compression zone describes a region of ____ in the medium, which is subjected to an ultrasound field.
Low pressure
Density is defined as
Mass per unit of volume
In a longitudinal wave the sound beam runs parallel or perpendicular to the direction of particle motion?
Parallel
Unit for pressure is?
Pascal (Pa)
In a transverse wave the sound beam runs parallel or perpendicular to the direction of particle motion?
Perpendicular
Which of the following are acoustic variables?
Pressure, motion of particles in the wave, density
An area of low pressure and particle density on a pressure wave is referred to as a ____.
Rarefaction
Negative amplitude of wave, an area of low pressure and particle density on a pressure wave is referred to as a:
Rarefaction
Which best describes sound waves?
Series of compressions and rarefactions
Which of the following types of waves require a medium in order to propagate?
Sound
All of the following statements are true regarding sound waves, except:
They are longitudinal, electromagnetic waves.
Sound is a mechanical longitudinal wave
True
Which of the following terms does not belong with the others?
Wider molecular spacing
As sound travels through a medium, what term describes the effects of the medium on the sound wave?
acoustic propagation properties
What are rarefactions?
areas of decreased pressure & density(regions of lower density & pressure)
What are compressions?
areas of increased pressure and density
Define pressure:
concentration of force within an area
Sound can be characterized as:
cyclical oscillations in certain variables
—— measure of particle motion
distance
What is the formula for pressure?
force/area
A particle within a transverse wave is traveling vertically. What is the direction of the wave's propagation?
horizontal
Two waves arrive at a location at the same time. What event takes place?
interference
Waves that exist at the same location and time will combine together. What is this called?
interference
When particle motion of a medium is parallel to the direction of a wave propagation, what is the wave being transmitted called?
longitudinal wave
Which of the following describes the characteristics of a sound wave?
mechanical, longitudinal
The acoustic variables are:
pressure, density, distance
All of the following are true about sound waves except:
they are transverse
Particles moving in a perpendicular direction (right angles or 90degrees) to the direction of the wave is called:
transverse wave
The direction of motion of a particle in a wave is perpendicular to the direction of propagation of the wave. What type of wave is this?
transverse wave
