Physics final exam study guide PDF

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Chapter Study Guides for exams for Dr A. Physics Class...

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PHYSICS FINAL EXAM STUDY GUIDE Exam 1: Ch 1 and 2 Chapter 1: The Basics 1. 2. 3. 4. 5. 6. 7.

Is the x-axis horizontal or vertical? The y-axis? a. X = horizonal; Y = vertical When one variable increases and the other decreases is it a direct or inverse relationship? a. Inverse Two variables that increase demonstrate what type of relationship? a. Directly related or directly proportional Define a reciprocal relationship. a. When two numbers equal 1 when multiplied together What is the reciprocal of 20? a. 1/20 A number in scientific notation form with an exponent of zero has a value of? a. Between 1 and 10 What is the complimentary metric unit for the following? a. Giga i. nano b. Deca i. Deci c. Milli i. Kilo d. Mega i. micro e. Centi i. Hecto

Ch. 2: Sound 1. 2. 3.

4. 5. 6. 7. 8.

In diagnostic ultrasound, sound pulses created by a transducer travel through ______. a. Media, biologic tissue What do waves transfer from one location to another? a. Energy Sound must travel through a medium where molecules are alternatively _____ and ______ a. Compressed – squeezed together b. Rarefied – stretched apart Are sound waves transverse or longitudinal? a. Longitudinal Define acoustic propagation properties a. The effects of the medium upon the sound wave What are the acoustic variables and what are their units ? a. Pressure (pascals), density (kg/cm3), distance (cm, ft, miles) Sound waves are also known as _____ a. Acoustic waves What are the acoustic parameters? a. Period, frequency, amplitude, power, intensity, wavelength, propagation speed

9. What are used to distinguish between sound waves and other types of waves? Acoustic Variables or acoustic parameters? a. Acoustic variables 10. What are used to describe the characteristics of a sound wave? a. Acoustic Parameters 11. When particles move in a direction perpendicular to direction that the wave propagates, what type of wave is it? a. Transverse 12. When particles move in the same direction that the wave propagates, it is a ______ wave. a. Longitudinal 13. Holding a close line and shaking it up and down creates which type of wave? a. Transverse 14. Pushing a slinky forward is an example of a _____ wave. a. Longitudinal 15. Describe the difference between in-phase and out-of-phase waves. a. A wave is In-phase when their maximum values (peaks) and minimum values occur at the same time and at the same location. Out-of-phases have peaks that occur at different times and so do their troughs 16. Describe interference a. When more than one sound beam travel in a medium and arrive at the same time, they lose their individual characteristics and combine to form a single wave 17. Both in-phase and out-of-phase wave pairs undergo interference. True or False a. True 18. What is the term for when a resulting wave is larger amplitude than either of its components? a. Constructive interference 19. The interference of a pair of ______ causes constructive interference a. In-phase waves 20. When the resultant wave in smaller than one if its components a. Destructive interference 21. The interference of a pair of _____ waves results in the formation of a single wave of lesser amplitude than at least one of its components a. Out of phase waves 22. What happens when two out-of-phase waves are of equal amplitude? a. Complete destructive interference 23. What happens when the frequencies of the waves differ? a. Both constructive and destructive interference 24. What units are used to report the pressure of a sound beam? a. Pascals 25. Acoustic variables allow us to determine which waves are sound and which are not. T or F a. True 26. Acoustic parameters are used to describe the features of sound waves? a. True 27. What is the unit for density ? a. Kg/cm3 - concentration of mass in a volume 28. What is the definition of pressure ? a. Concentration of force in an area 29. Definition of distance a. Measure of particle motion

Exam 2: Ch 3 & 4

Ch 3: Describing Sound Waves 1) Parameters describe ____ of sound waves. a) Features 2) List the 7 parameters a) Period b) Frequency c) Amplitude d) Power e) Intensity f) Wavelength g) Speed (propagation speed) 3) Define period a) Time it takes for a wave to vibrate a single cycle, start of one cycle to the start of the next cycle 4) What are the units for period a) Time; seconds or microseconds 5) True or False, period is determined by the sound source and medium. a) False, period is determined only by the sound source 6) Can sonographer adjust period? a) No 7) Define frequency a) The number of particular events (waves) that occur in a specific duration of time 8) What are the units for frequency? a) Hz or units per second … cycles per second 9) Typical values for freq? a) 2 MHz – 15 Mhz 10) True or false, the sonographer can change the frequency a) No 11) Frequency of a sound wave is determined by the _____. a) Sound source 12) Sound waves with frequencies under _____ Hz are infrasound. a) 20 Hz 13) A sound wave that has a frequency above 20,000 Hz or 20 KHz is ____ a) Ultrasound 14) In diagnostic ultrasound, the frequency has to be at least _____ a) 2MHz

15) What is the range for audible sound a) 20hz – 20,000hz or 20hz - 20KHz 16) As frequency increases, period _____ a) Decreases 17) What is a reciprocal relationship? a) When two numbers multiply together and equal one. 18) What would the complimentary unit for hertz be when using milliseconds? a) Killohertz 19) List the three “bigness” parameters. a) Amplitude, Power, Intensity 20) What is the difference between amplitude and peak-to-peak amp? a) Amp is the difference of the avg of the wave (middle or x axis) and the max or mix value. “halfway point”. Peak-to-peak measure the max to the min peak 21) In ultrasound, what is the unit for amplitude? a) Db Decibels 22) Amplitude can have units of any of the _____. a) Acoustic variables 23) What are the acoustic variables and their corresponding units? a) Pressure - pascals (pa) b) Density – kg/cm3 c) Distance - mm, cm 24) Initially, amp is determined on by the _____. a) Sound source 25) Define power a) Rate of energy transfer or rate at which work is performed 26) How are power and amplitude related? a) As power increases, amplitude increases b) Power is proportional to the wave’s amplitude squared c) Power α Amplitude2 27) Define intensity a) Concentration of energy in a sound beam 28) Equation for Intensity ? a) Intensity (W/cm2) = power (w) / area (cm2) 29) The word squared always follows (power, intensity, amplitude)? a) Amplitude 30) If intensity increase, Power _____ a) Increases 31) What is the only parameter determined by both source and medium? a) Wavelength 32) What is the difference between wavelength and period? How are they similar ? a) They both are talking about one cycle or one wave b) Wavelength is distance of one wave, period is time for one wave to occur. units are different 33) Typical value for wavelength ?

a) 0.1 - 0.8mm 34) In soft tissue, sound with a freq of ___ has a wavelength of _____ a) 1 MHz, 1.54mm 35) As wavelength increase, frequency _____ a) Decreases 36) Equation for wavelength of a sound in soft tissue? a) Wavelength (mm) = 1.54mm/µ / frequency (MHz) 37) Shorter wavelength produces a ____ quality image a) Higher; shorter wavelength has a high freq and we know high freq creates sharper image but not as deep of penetration 38) What parameter is the rate at which sound wave travels through a medium a) Propagation speed 39) The typical values of the propagation speed depends on the _____ a) Tissues 40) Three waves of different frequency are traveling through the same medium, how is their speed affected? a) The speed will be the same bc it is traveling through the same medium or tissue 41) What is the speed of sound in soft tissue? a) 1540m/s 42) List tissue type is order from slowest speed to fastest a) Lung, fat, soft tissue, liver, blood, muscle tendon, bone 43) What has a higher prop speed, fat or bone? a) Bone 44) List in order from fastest to slowest prop speed: Liquid, Solid, Gas a) Solid, liquid, gas 45) Equation for speed? a) Speed (m/s) = freq (Hz) x wavelength (m) 46) What two characteristics of a medium determine the speed of sound in that medium? a) Stiffness and density 47) Density and speed are ____ related a) Inversely 48) Speed and stiffness are ____ related a) Directly 49) Which factor is more important, stiffness or density? a) Stiffness has greatest influence on speed

Ch 4. Describing Pulse Waves 1) What are the 5 additional parameters to describe pulse waves? a. Pulse duration b. Pulse repetition period c. Pulse repetition freq d. Duty factor e. Spatial pulse length

2) Two components of pulsed ultrasound a. Transmit and receiving AKA talking and listening 3) What is a pulse sound? a. A collection of cycles that travel together 4) Can the pulse duration change for a single transducer? a. No, each transducer emits a pulse with a fixed duration 5) Define pulse duration a. Actual time from start of pulse to end of that pulse. The talking time 6) Is pulse duration adjustable? a. No not while using a particular ultrasound transducer 7) Pulse duration is equal to ____ x ____ a. # of cycles x period (microseconds) 8) What unit do you use for pulse duration? a. Time, seconds 9) Pulse duration is ____ proportional to the number of cycles in the pulse and _____ proportional to the period. It is also _____ proportional to frequency. a. Directly, directly, inversely 10) What two characteristics create pulses of long duration? a. Many cycles in the pulse OR individual cycles with long periods 11) Which type of pulse is more desirable for imaging? a. Short duration because they create images of higher freq 12) Define spatial pulse length a. Distance from start to end of pulse 13) Difference between pulse duration and spatial pulse length? a. Units, pulse duration is time of a pulse and spatial pulse length is distance 14) What is spatial pulse length determined by? a. Both source and medium 15) Spatial pulse length equals _____ x _____ a. # of cycles x wavelength (mm) 16) Spatial pulse length is ____ related to freq a. Inversely 17) True false, pulses of shorter wavelength are more desirable. a. True, they create more accurate images 18) Define pulse repetition period a. Time from start of one pulse to the start of the next pulse 19) Pulse repetition period is determined by ____ a. Imaging depth 20) When the system is imaging more deeply, the time from one pulse to the next is _____ a. Longer 21) Pulse rep period and imaging depth are ____ related a. Directly 22) Transmit time is called the ______ a. Pulse duration 23) With deeper imaging, the listening time and the pulse rep period ______

a. lengthen 24) When sonographer adjusts the depth, is the transmit time or pulse duration changed? a. No 25) What is PRF? a. pulse repetition freq, # of pulses that ultrasound system transmits into body each second 26) True of False, PRF is related to frequency a. False; only related to depth of view 27) When the system is imaging shallow, the pulse repetition freq is ____ a. Higher 28) Pulse rep freq and depth of view are ____ related a. Inversely 29) PRP and _____ have a reciprocal relationship. a. PRF 30) A shorter pulse rep period results in a _____ pulse rep freq a. Higher 31) Define duty factor a. Percentage or fraction of time that the system transmits a pulse 32) Units for duty factor? a. None 33) Can sonographer change duty factor? a. Yes 34) Duty factor is inversely related to ____ a. Imaging depth 35) Duty factor (%) = a. Pulse duration / PRP x 100 36) How does the sonographer change duty factor? a. When the imaging depth is altered 37) As imaging depth increases, transmit time or pulsed duration, _____ while listening time is ______ a. Remains constant; prolonged 38) Shallow imaging has ____ listening, ____ PRP, ____ PRF, ____ duty factor a. less, shorter, higher, higher 39) The parameters that describe a single cycle can describe both pulsed and continuous wave sounds and those parameters are ________ a. Period, freq, wavelength, propagation speed

Exam 3: Ch 5 (and some of ch 6) Ch 5: Intensity 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

15. 16. 17. 18.

Intensity: a. Beam power/area Equation for intensity a. I (w/cm2) = P (w) / area (cm2) Spatial: a. Distance or space. US beam doesn’t have same intensity at different locations Temporal: a. All time; transmit and receive. Does a small area have lots of intensity or little? a. Lots. as area decreases, intensity increases. inversely related Peak: a. Max value Avg: a. Mathematical middle value Pulsed: a. Only transmit time Another name for pulsed? a. Pulsed duration The different measurements of intensities are important in the study of ____. a. Bioeffects Two ways to report spatial intensity? a. Isp Isa The beams intensity at location where it is max? a. Isp spatial peak intensity What is Isa ? a. Spatial average intensity. average intensity across entire beam’s cross sectional What are the 4 methods for measuring temporal intensity? a. Itp temporal peak b. Imax c. Ipa pulsed average d. Ita temporal avg What is Imax? a. Avg intensity during most intense half-circle What intensity is taken only during transmit time? a. Ipa pulsed avg Which is higher, Ipa or Ita? a. Ipa bc no zero / listening time to bring down the average Which is the intensity during entire pulse rep period?

a. Ita – temporal avg. both transmit and receive time 19. Which is the highest out of all 4? a. Itp – peak is max value 20. Which is lowest? a. Ita 21. List the temporal intensities highest to lowest a. Itp, Imax, Ipa, Ita 22. What are two ways of showing peak intensity? a. Itp and Imax 23. Why is Ipa lower than Imax? a. It includes an average over entire pulse duration including less intense tail end 24. The temporal avg Ita is up to _____ times ____ than the others a. 500, lower 25. What is the duty factor of pulsed US systems? a. 0.2%, --> 99.8% of time is spent listening/silent and intensity is 0 26. Isptp a. At location where intensity is max and at the instant of time its most powerful 27. What is the lowest method of representing intensity? a. IsaIta this is two averages with the temporal measuring listening time and transmit time 28. Which is highest? a. IspItp two peaks/max values 29. What is measured at location where intensity is max averaged over transmit time? a. SPPA 30. What is measured over entire cross sectional area of sound beam and over all time? a. SATA 31. SPTA? a. Measured at location where intensity is max averaged over all time (trans and receive) 32. Units for intensity ? a. W/cm2 33. What are the 6 methods of medsurg and reporting intensities? a. SPTA, SATP, SPPA, SPPA, SAPA, SPTA, SATA 34. Intensities may be reported in various ways with respect to ____ and _____ a. Time and space 35. What is the most relevant intensity with respect to tissue heating? a. SPTA 36. The spread of a beam in space? a. Beam uniformity coefficient 37. What is BUC also called? a. SP/SA factor 38. Units for SP/SA? a. Unitless. Will be number 1 or greater 39. What describes relationship of beam intensities with time? a. Duty factor. pulse duration/prp x 100

40. Units for duty dactor? a. Unitless. between 0-1 41. In a continuous wave, what is the pulse avg and temp avg? Which is bigger? a. They are the same 42. In a continuous wave, SPTA = a. SPPA 43. In a continuous wave, SAPA = a. SATA 44. When pulsed and contiuous waves have the same SPTP, continuous wave has higher _____ a. SPTA 45. When pulsed and continuous waves have the same SATP, ________ a. Continuous has higher SATA 46. Rank of intensities from largest to smallest? a. SPTP, Im, SPPA, SPTA, SATA 47. As sound saves propagate they may also _____ a. Change direction 48. Sound waves weaken or _____ as they travel through body a. attenuate 49. After sound wave is turned into electrical signal when its received, its sent to U/S system where it is strengthened, or ______ a. Amplified 50. Standard tool to report changes in attenuation or amplification? a. Decibel notation 51. Decibels are based on math construct called______ a. Logarithms 52. What is logarithm? a. Novel method of rating numbers 53. What does the log of a number represent? a. The number of 10s that are multiplied together to create original number 54. A decibel notation is _____ a. A relative measurement, comparison, logarithmic 55. Decibels report ______ changes a. Relative 56. Decibels require _____ intensities a. 2 57. Decibels are a ration, what is divided by what? a. Measured level divided by starting level. (final/initial) 58. Positive decibels report a. Signals getting larger/increasing 59. When wave intensity doubles, relative change is _____ a. +3dB 60. When wave intensity increases 10 fold? a. +10db 61. Write out intensity decibel/log chart

30.

x1000

20.

x100

10.

x10

9.

x8

6.

x4

3.

x2

-3.

x1/2

-6.

x1/4

-9.

x1/8

-10.

x1/10

-20

x1/100

-30. x1/1000 62. When intensity is reduced to ½ its original value, the relative change is a. -3db 63. Attenuation is a decrease is _____, _____, and _______ a. Power, intensity, amplitude 64. Attenuation is determined by what 2 factors? a. Path length and frequency of sound 65. Distance and attenuation are ___ related a. Directly. (as you go further into the body sound weakens) 66. Frequency and attenuation are_____ related a. Directly related 67. What are the three processes that contribute to attenuation ? a. Reflection, scattering, absorption 68. When is reflection likely to occur? a. When dimension of boundary is large, more than a few wavelengths of sound 69. 2 forms of reflection? a. Specular and diffuse 70. specular reflection occurs when boundary is ____. the sound is reflected in _____ direction(s) in an ______ matter a. Smooth; one; organized 71. Diffuse reflection occurs when a wave is reflected off a _____ surface a. Irregular 72. What is another name for diffuse reflection? a. Backscatter 73. What is a disadvantage of diffuse reflection a. Backscattered signals have lower strength than specular 74. What is scattering?

a. Random redirection of sound in many directions 75. When does sound scatter? a. When tissue interface is small. equal to or less than wavelength of the incident sound beam 76. What is an example if a tissue that causes scattering? Why? a. Lung. alveoli is filled with air 77. Which scatters more high freq or low freq? a. High 78. Scattering is _____ related to frequency a. Directly 79. What is Rayleigh scattering? a. Occurs when structures dimension are much smaller than beams wavelength 80. What does sound beam do in rayleigh scattering? a. Redirects equally in all directions “omnidirectional” 81. Is diffuse/backscatter organized or disorganized? Does sound travel back to transducer or go in all directions? a. Unorganized. sound travels back to transducer 82. What is an example of something in the body that causes rayleigh scattering? a. Red blood cells 83. How are frequency and rayleigh scattering related? a. High frequency dramatically increases rayleigh scattering 84. What is equaltion for rayleigh scattering? a. Raylaigh scattering ∝ frequency4

85. The goal in diagnostic imaging is to use the ____ freq that still provides images to depth of structures a. Highest 86. Absorption occurs when ________ a. US energy is concerted into another energy form such as heat 87. Absoprtion is _____ related to freq a. Directly 88. As a result of absorption, _____ freq waves attenuate more than _____ freq a. Higher; lower 89. What in the body undergoes significant absorption? a. Bone

Exam 4: Ch 6 & 7 1. 2. 3. 4.

5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

18. 19. 20.

Attenuation coefficient: a. Number of decibels of attenuation that occurs when sound travels one centimeter Units for attenuation coefficient a. dB/cm Advantage of describing sound weakening with an attenuation coefficient? a. Value rema...