Exam Practice Guide Units 1 & 2 Physics: Detailed Study 5 - Investigations: Medical physics Examination Questions Key Features: 22 original examination style questions on all examinable topics. Full solutions and a marking guide to all questions. Separated into key topic areas within each Area of Study, enabling students to master one topic at a time. Written by VCE assessors who mark the real examinations. Excellent resource for examination practice. Helping VCE students be the best they can be.
EXAM PRACTICE GUIDE - Units 1 & 2 Physics: Detailed Study 6: Investigations: Medical physics 2 Copyright TSSM 2013 TSSM ACN 099 422 670 ABN 54 099 422 670 A: Level 14, 474 Flinders Street Melbourne VIC 3000 T: 1300 134 518 F: 03 97084354 W: tssm.com.au E:info@tssm.com.au
EXAM PRACTICE GUIDE - Units 1 & 2 Physics: Detailed Study 6: Investigations: Medical physics 3 CONTENTS Page Questions 4 Solutions 9
EXAM PRACTICE GUIDE - Units 1 & 2 Physics: Detailed Study 6: Investigations: Medical physics 4 Question 1 An ultrasound device is being used to look at the structure of some soft tissue. Determine the intensity of the pulse that is reflected after encountering a boundary between soft tissue and muscle. The intensity of the original pulse was 100 Wm -2. Acoustic impedance of soft tissue = 1.63 x 10 6 kgm -2 s -1 Acoustic impedance of muscle = 1.71 x 10 6 kgm -2 s -1 A. 5.74 x 10-2 Wm -2 B. 9.53 x 10-1 Wm -2 C. 5.74 x 10-4 Wm -2 D. 2.40 Wm-2 2 marks Question 2 Which of the following statements is most accurate for the reflected pulse mentioned in Question 1? A. It is very likely that this will show up on the ultrasound because the difference in acoustic impedance between the soft tissue and the muscle is so small that very little of the pulse will be reflected. B. It is very likely that this will show up on the ultrasound because the difference in acoustic impedance between the soft tissue and the muscle is so large that a great amount of the pulse will be reflected. C. It is very unlikely that this will show up on the ultrasound because the difference in acoustic impedance between the soft tissue and the muscle is so large that a great deal of the pulse will be reflected. D. It is very unlikely that this will show up on the ultrasound because the difference in acoustic impedance between the soft tissue and the muscle is so small that very little of the pulse will be reflected. 2 marks Question 3 The reason that audible sound is not used for ultrasound is best explained by which of the following? A. Greater resolution is achieved through ultrasound, due to its lower frequency B. Greater resolution is achieved through ultrasound, due to its higher intensity C. Improved penetration is achieved through ultrasound, due to its longer wavelength D. Greater resolution is achieved through ultrasound, due to its higher frequency
EXAM PRACTICE GUIDE - Units 1 & 2 Physics: Detailed Study 6: Investigations: Medical physics 5 Question 4 Which of the following best describes the process by which ultrasound is produced? A. The piezoelectric effect is achieved by vibrating specific crystal, which creates voltage as a result B. The piezoelectric effect is achieved by applying voltage across specific crystals, which change shape and vibrate as a result C. Particular isotopes decay, emitting a positron which leads to high frequency gamma radiation D. Resonating crystals used to emit short bursts of high frequency radio waves Question 5 Hard X-Rays: A. have higher wavelengths than soft X-rays B. penetrate further than soft X-rays C. are the same as soft X-rays D. don t exist 1 mark Question 6 A particular X-Ray photon has an energy of 3.50 x 10-15 J. What is the frequency of this X-Ray photon? A. 1.70 x 10 3 Hz B. 5.27x 10-50 Hz C. 5.28 x 10 18 Hz D. 4.21 x 10 18 Hz 2 marks Question 7 Which of the following scans would be least suited to x-ray imaging? A. Bone B. Routine lung scan C. Soft tissue of the abdomen D. Heart and circulation (with a contrast medium) Question 8 Which of the following gives the best description of an endoscope? A. A hand held panel used for generating and detecting ultrasound frequencies B. A small manoeuvrable tube with a sensor or camera attached to one end C. A small manoeuvrable tube that emits radio pulses D. A large flat paddle capable of delivering a short pulse of electric current to a surface it is in contact with 1 mark