LRA 222 Exam Study Questions with 100% Correct Answers

LRA 222 Exam Study Questions with 100% Correct Answers 1. T/F To produce x-rays, a cloud of electrons are necessary and the cathode must have a strong positive charge. - ANSWER False 2. Grids are typically used when: - ANSWER part measures more than 10 cm and at least 60 kVp needed for the exam only. 3. Grids absorb scatter radiation because the scattered photons - ANSWER travel at an angle to the transmitted photons. 4. The number of lead lines per inch or centimeter is the grid - ANSWER frequency. 5. The relationship between the height of the lead strips and the distance between them is the grid - ANSWER ratio. 6. Which of the following is the formula used to determine grid ratio? - ANSWER Grid ratio = height of the lead strips/distance between the lead strips 7. What is the grid ratio if the lead strips are 2.4 mm high, 0.02 mm wide, and 0.3 mm apart? - ANSWER 8:1 8. Using a higher the grid ratio will - ANSWER increase scatter clean up and increase radiographic contrast only. 9. Linear grids are the most commonly used because - ANSWER the tube can be angled in the direction of the lead lines. 10. A grid with lead strips that run parallel to each other is a - ANSWER parallel grid and nonfocused grid. 11. The distance between the grid and the convergent line is the - ANSWER focal distance 12. The recommended SIDs that can be used with a focused grid is the - ANSWER focal range 13. If all the convergent points were connected along the length of the grid they would form the - ANSWER convergent line. 14. An IR that has a grid permanently attached to its front surface is a - ANSWER grid cassette 15. The grid is part of a device located just below the tabletop that also includes a tray to hold the IR. This device is the - ANSWER bucky. 16. To compensate for the reduction of radiation reaching the IR when a grid is used, ___________ is typically increased. - ANSWER mAs 17. The primary side of the high-voltage transformer is found on the - ANSWER primary circuit 18. T/F The stator is made up of electromagnets. - ANSWER True 19. T/F The effective focal spot is smaller than the actual focal spot because the face of the anode is angled. - ANSWER True 20. The cathode includes the - ANSWER filaments and the focusing cup 21. The purpose of the filament circuit is to - ANSWER boil electrons off the filament 22. The devices that change alternating to direct current are the - ANSWER rectifiers 23. The focusing cup is able to keep the electrons together because - ANSWER like charges repel 24. The step-down transformer is found on the - ANSWER filament circuit 25. The x-ray tube (not filaments) is found on the - ANSWER secondary circuit 26. The timer circuit is found on the - ANSWER primary circuit 27. Place the following events leading to the production of x-rays in order, from first to last: I. II. III. electrons are boiled off filament electricity leaves the autotransformer electricity goes to primary side of step-down transformer IV. filament is heated - ANSWER II. electricity leaves the autotransformer III. electricity goes to primary side of step-down transformer IV. filament is heated V. electrons are boiled off filament 28. Electromagnetic radiation - ANSWER has no mass 29. T.F Prepping the rotor but not making an exposure on a regular basis is related to tube damage or failure. - ANSWER True 30. The motor that turns the anode operates through - ANSWER mutual induction 31. The device that adjusts the incoming power supplied to the x-ray circuit to maintain 220 V is the - ANSWER line compensator 32. The device used to absorb scatter radiation in the radiation leaving the patient before it reaches the image receptor is the - ANSWER grid 33. The beam-restriction device that results in images with the most unsharpness around the edge of the image is the - ANSWER aperture diaphragm 34. A flat piece of lead with a hole in it that has a flange directed toward the patient is a(n) - ANSWER cone or cylinder 35. For radiographic procedures, scatter radiation is primarily the result of - ANSWER Compton interaction 36. The automatic collimator - ANSWER automatically collimates to the IR size