CHAPTER 01: INTRODUCTION TO THE IMAGING
SCIENCES
JOHNSTON: ESSENTIALS OF RADIOGRAPHIC
PHYSICS AND IMAGING, 2ND EDITION 2025/2026
LATEST UPDATE WITH Q&A
1. Exposure times for very early radiographs ranged from
a. 1 second to 5 seconds
b. 1 minute to 15 minutes
c. 20 minutes to 2 hours
d. 2 hours to 5 hours
ANS: C
Exposure times for early radiographs took from 20 minutes to 2 hours to
produce an image.
REF: 3 OBJ: 1
2. Acute radiodermatitis was
a. the radiation burn resulting from excessive exposure to x-rays
Page 1 of 45
,b. common among early patients and operators of x-ray equipment
c. a delayed reaction to excessive x-ray exposure
d. all of the above
ANS: D
Early on, the excessive radiation exposure to many operators and patients
resulted in radiation burns, a delayed response to the exposure.
REF: 3 OBJ: 1
3. Who brought attention to the dangers of x-rays?
a. Wilhelm Roentgen.
b. Bertha Roentgen.
c. Crookes.
d. Thomas Edison.
ANS: D
Thomas Edison, the famous American inventor, suffered a radiation burn and
brought attention to the dangers of x-rays.
REF: 3 OBJ: 1
Page 2 of 45
, 4. An example of how x-rays were used for entertainment or business
gain in a dangerous manner was the
a. fluoroscopic shoe fitter
b. x-ray stove polish
c. x-ray headache tablets
d. x-ray golf balls
ANS: A
Although the stove polish, headache tablets, and golf balls used “x-ray” in their
names, the shoe fitter actually exposed shoppers to radiation.
REF: 4 OBJ: 1
5. Mass, length, and time are considered
a. fundamental quantities
b. derived quantities
c. radiologic quantities
d. none of the above
Page 3 of 45
, ANS: A
Mass, length, and time are the most basic or fundamental quantities.
REF: 5 OBJ: 2
6. X-rays were discovered
a. November 8, 1805
b. November 8, 1875
c. November 8, 1895
d. November 8, 1985
ANS: C
X-rays were discovered November 8, 1895.
REF: 1 OBJ: 1
7. Barium platinocyanide was the material in Dr. Roentgen’s laboratory
that
a. covered the cathode ray tube
Page 4 of 45
SCIENCES
JOHNSTON: ESSENTIALS OF RADIOGRAPHIC
PHYSICS AND IMAGING, 2ND EDITION 2025/2026
LATEST UPDATE WITH Q&A
1. Exposure times for very early radiographs ranged from
a. 1 second to 5 seconds
b. 1 minute to 15 minutes
c. 20 minutes to 2 hours
d. 2 hours to 5 hours
ANS: C
Exposure times for early radiographs took from 20 minutes to 2 hours to
produce an image.
REF: 3 OBJ: 1
2. Acute radiodermatitis was
a. the radiation burn resulting from excessive exposure to x-rays
Page 1 of 45
,b. common among early patients and operators of x-ray equipment
c. a delayed reaction to excessive x-ray exposure
d. all of the above
ANS: D
Early on, the excessive radiation exposure to many operators and patients
resulted in radiation burns, a delayed response to the exposure.
REF: 3 OBJ: 1
3. Who brought attention to the dangers of x-rays?
a. Wilhelm Roentgen.
b. Bertha Roentgen.
c. Crookes.
d. Thomas Edison.
ANS: D
Thomas Edison, the famous American inventor, suffered a radiation burn and
brought attention to the dangers of x-rays.
REF: 3 OBJ: 1
Page 2 of 45
, 4. An example of how x-rays were used for entertainment or business
gain in a dangerous manner was the
a. fluoroscopic shoe fitter
b. x-ray stove polish
c. x-ray headache tablets
d. x-ray golf balls
ANS: A
Although the stove polish, headache tablets, and golf balls used “x-ray” in their
names, the shoe fitter actually exposed shoppers to radiation.
REF: 4 OBJ: 1
5. Mass, length, and time are considered
a. fundamental quantities
b. derived quantities
c. radiologic quantities
d. none of the above
Page 3 of 45
, ANS: A
Mass, length, and time are the most basic or fundamental quantities.
REF: 5 OBJ: 2
6. X-rays were discovered
a. November 8, 1805
b. November 8, 1875
c. November 8, 1895
d. November 8, 1985
ANS: C
X-rays were discovered November 8, 1895.
REF: 1 OBJ: 1
7. Barium platinocyanide was the material in Dr. Roentgen’s laboratory
that
a. covered the cathode ray tube
Page 4 of 45
