BXMO Basic X-Ray Machine Operator Exam | Latest Update
2026/2027 | 200 Practice Questions with Rationales | 100% Correct |
Grade A+
1. The boxlike device attached under the tube housing that allows the limited operator to vary the size
of the radiation field is called the:
- A. Bucky
- B. Grid
- C. Collimator
- D. Filter
Answer: C. Collimator
Rationale: The collimator is attached below the x-ray tube housing and contains adjustable lead shutters
that allow the operator to control the size and shape of the radiation field, reducing patient exposure
and improving image quality.
2. An invisible line in the center of the x-ray beam and perpendicular to the long axis of the x-ray tube is
called the:
- A. Transverse line
- B. Central ray
- C. Central axis
- D. Sagittal line
Answer: B. Central ray
Rationale: The central ray is the imaginary line in the center of the x-ray beam that is perpendicular to
the long axis of the x-ray tube, used to center the beam to the image receptor and patient anatomy.
,3. An exposure time of 0.02 seconds is equal to how many milliseconds?
- A. 200 msec
- B. 2 msec
- C. 2000 msec
- D. 20 msec
Answer: D. 20 msec
Rationale: 0.02 seconds × 1000 milliseconds/second = 20 milliseconds. This conversion is critical for
timing accuracy in radiographic exposures.
4. When 62 kVp is increased by 30%, the result is approximately:
- A. 80 kVp
- B. 62 kVp
- C. 90 kVp
- D. 81 kVp
Answer: D. 81 kVp
Rationale: 30% of 62 is 18.6; 62 + 18.6 = 80.6, approximately 81 kVp. This type of calculation is used
when adjusting technique for patient size variations.
5. When the fraction 7/8 is converted to a decimal, the result is:
- A. 0.875
- B. 0.700
- C. 0.800
,- D. 0.750
Answer: A. 0.875
Rationale: 7 divided by 8 equals 0.875. Understanding fraction-to-decimal conversion is important for
calculating exposure factors and mAs values.
6. When 230% is expressed as a decimal, the result is:
- A. 0.23
- B. 23.0
- C. 0.023
- D. 2.3
Answer: D. 2.3
Rationale: 230% = 230/100 = 2.3. Percentage conversions are used when calculating technique changes
for patient size or pathology adjustments.
7. A radiographic image is made using 500 mA, 0.1 sec., 80 kVp, and 48-inch SID. The value of the mAs
for this exposure is:
- A. 50 mAs
- B. 5 mAs
- C. 500 mAs
- D. 0.5 mAs
Answer: A. 50 mAs
Rationale: mAs = mA × time = 500 × 0.1 = 50 mAs.
, 8. The number 9 squared is equal to:
- A. 81
- B. 18
- C. 9
- D. 27
Answer: A. 81
Rationale: 9² = 9 × 9 = 81.
9. The number 4 is the square root of:
- A. 2
- B. 4
- C. 16
- D. 8
Answer: C. 16
Rationale: The square root of 16 is 4.
10. Which of the following would be considered a characteristic of x-rays?
- A. Have mass and are positively charged
- B. Have mass and are negatively charged
- C. Have no mass and are electrically neutral
- D. Travel in curved lines
2026/2027 | 200 Practice Questions with Rationales | 100% Correct |
Grade A+
1. The boxlike device attached under the tube housing that allows the limited operator to vary the size
of the radiation field is called the:
- A. Bucky
- B. Grid
- C. Collimator
- D. Filter
Answer: C. Collimator
Rationale: The collimator is attached below the x-ray tube housing and contains adjustable lead shutters
that allow the operator to control the size and shape of the radiation field, reducing patient exposure
and improving image quality.
2. An invisible line in the center of the x-ray beam and perpendicular to the long axis of the x-ray tube is
called the:
- A. Transverse line
- B. Central ray
- C. Central axis
- D. Sagittal line
Answer: B. Central ray
Rationale: The central ray is the imaginary line in the center of the x-ray beam that is perpendicular to
the long axis of the x-ray tube, used to center the beam to the image receptor and patient anatomy.
,3. An exposure time of 0.02 seconds is equal to how many milliseconds?
- A. 200 msec
- B. 2 msec
- C. 2000 msec
- D. 20 msec
Answer: D. 20 msec
Rationale: 0.02 seconds × 1000 milliseconds/second = 20 milliseconds. This conversion is critical for
timing accuracy in radiographic exposures.
4. When 62 kVp is increased by 30%, the result is approximately:
- A. 80 kVp
- B. 62 kVp
- C. 90 kVp
- D. 81 kVp
Answer: D. 81 kVp
Rationale: 30% of 62 is 18.6; 62 + 18.6 = 80.6, approximately 81 kVp. This type of calculation is used
when adjusting technique for patient size variations.
5. When the fraction 7/8 is converted to a decimal, the result is:
- A. 0.875
- B. 0.700
- C. 0.800
,- D. 0.750
Answer: A. 0.875
Rationale: 7 divided by 8 equals 0.875. Understanding fraction-to-decimal conversion is important for
calculating exposure factors and mAs values.
6. When 230% is expressed as a decimal, the result is:
- A. 0.23
- B. 23.0
- C. 0.023
- D. 2.3
Answer: D. 2.3
Rationale: 230% = 230/100 = 2.3. Percentage conversions are used when calculating technique changes
for patient size or pathology adjustments.
7. A radiographic image is made using 500 mA, 0.1 sec., 80 kVp, and 48-inch SID. The value of the mAs
for this exposure is:
- A. 50 mAs
- B. 5 mAs
- C. 500 mAs
- D. 0.5 mAs
Answer: A. 50 mAs
Rationale: mAs = mA × time = 500 × 0.1 = 50 mAs.
, 8. The number 9 squared is equal to:
- A. 81
- B. 18
- C. 9
- D. 27
Answer: A. 81
Rationale: 9² = 9 × 9 = 81.
9. The number 4 is the square root of:
- A. 2
- B. 4
- C. 16
- D. 8
Answer: C. 16
Rationale: The square root of 16 is 4.
10. Which of the following would be considered a characteristic of x-rays?
- A. Have mass and are positively charged
- B. Have mass and are negatively charged
- C. Have no mass and are electrically neutral
- D. Travel in curved lines
