## Exercises Lesson

INSTRUCTIONS. Answer the following exercises by marking the lettered response that best answers the question or best completes the incomplete statement or by writing the answer in the space provided.

After you have completed all of these exercises, turn to "Solutions to Exercises" at the end of the lesson and check your answers. For each exercise answered incorrectly, reread the material referenced with the solution.

1. Which of the following combinations would produce 30 mAs?

 Seconds mA a. 1/60. 500 b. 3/20. 200 c. 5/20. 200 d. 4/10. 200

2. To effect a moderate increase in the density of a radiograph, with the kVp and processing remaining constant, you should normally use:

b. Faster intensifying screens.

c. A larger focal spot.

d. A doubled mAs.

3. Which of the following most accurately states the reciprocity law?

a. Change in density = 0.35 x milliamperage.

b. Emulsion reaction = time x light intensity.

c. Milliamperes x time = time x milliamperes.

d. 1/2 milliamperes x time = milliamperes x 1/2 exposure time.

4. Suppose a technique of 50 mA and an exposure time of 0.0 second is used for a radiograph. For a second exposure, the sec is decreased to 0.2 second. What mA should be used to keep the same film density?

 a. 120 mA. b. 150 mA. c. 175 mA. d. 200 mA.

5. Increasing exposure time would cause, primarily:

a. More contrast.

b. A decrease in fog.

c. An improvement in detail.

d. An increase in density.

6. Which of these factors has most to do with determining the size and shape of an image on a radiograph?

a. Source-to-image distance.

b. Focal-spot size.

c. Object-film distance.

d. Crystal size of screens.

7. The most noticeable difference between a radiograph and a shadow is the:

a. Outline of the image.

b. Silhouette effect.

c. Length of exposure time.

d. Presence of detail.

8. Focal spot size affects:

a. Density.

b. Distortion.

c. Contrast.

d. Definition.

9. The advantage of using a compression band when radiographing the abdomen is that it permits:

a. No involuntary motion.

b. Reduction of exposure time.

c. Improvement of contrast.

d. The patient to continue breathing during exposure.

10. When it is permissible to use movement in tissues as a diagnostic aid.

a. When desiring to blur out details.

b. When the body part cannot be immobilized.

c. When movement is due to equipment vibration.

d. When the patient is in traction.

11. One reason it is impossible to remove all distortion from a radiograph is that the:

a. Body tissues have varying densities.

b. Body is irregularly shaped.

c. Focal spot is not a point source.

d. Use of a filter diffuses the primary beam.

12. Proper use of which of the following sets of variables will best serve to minimize magnified distortion?

a. Focus-film and object-film distance.

b. Source-to-image distance and focal-spot size.

c. Focal-spot and screen crystal sizes.

d. Focal-spot size and object-film distance.

a. Increased film detail.

b. Increased body part penetration.

c. Shorter exposure time.

d. No change needed in technique factors

14. What protective measure built into a cardboard holder or cassette prevents fogging of the x-ray film by secondary radiation?

a. Aluminum sheet.

b. Bakelite strip.

c. X-ray absorbing film envelope.

15. Intensifying screens aid in the exposing of an x-ray film by:

a. Changing the x-rays to photons b. Emitting blue light, increasing the photographic effect c. Converting x-rays to corpuscular rays d. Increasing the sensitivity of the film emulsion.

16. What type of intensifying screens produces the best detail?

a. Slow speed b. High speed c. Medium speed d. Optimum speed

17. What happens when the intensifying screens and film are not in good contact?

a. Pressure points destroy the image.

b. The x-ray image is blurred.

c. Image is too light.

d. The x-ray image is uneven.

18. Which, if any, of the following named preparations is recommended for use in cleaning washable intensifying screens?

a. Manufacturer's solution.

b. Pure grain alcohol.

c. Barium platinocyanide.

d. Soap and water.

19. When standardizing a radiographic technique for a given body part, which factor should remain as the variably.

20. You are viewing a radiograph and notice an overall grayness with low contrast. This may be caused by:

a. Overexposure and short development.

b. Short exposure time.

c. Using the low kVp range.

d. Improper mA setting.