Download chapter 5—x-ray equipment

CHAPTER 5—X-RAY EQUIPMENT
TRUE/FALSE
1. Therapeutic equipment operates at much lower energies than diagnostic equipment.
ANS: F
DIF: Easy
2. Therapy equipment operates at high voltages and low amperages.
ANS: T
DIF: Easy
3. Floating tops can be moved when an electromagnetic brake is engaged.
ANS: F
DIF: Easy
4. The telescoping column of the overhead suspension system controls horizontal movement.
ANS: F
DIF: Easy
5. A head unit consists of a bucky tray and an x-ray tube.
ANS: T
DIF: Medium
6. In the United States, the incoming line voltage to an x-ray unit is approximately 120 volts.
ANS: F
DIF: Easy
7. The root mean square voltage of a single-phase sinusoidal wave is usually given as 70.7% of the peak
voltage.
ANS: T
DIF: Medium
8. During three-phase power, the overall potential difference drops to zero.
ANS: F
DIF: Easy
MULTIPLE CHOICE
1. How many alterations in the direction of the current flow occur per second in a 60-Hz AC current?
a. 20
c. 90
b. 60
d. 120
ANS: D
DIF: Medium
2. At what point in the x-ray circuit is the rectification circuit located?
a. between the semiconductors and the valve tubes
b. between the step-down transformer and the rheostat
c. between the step-up transformer and the x-ray tube
d. between the thermionic diode tubes and the x-ray machines
ANS: C
DIF: Medium
3. Where is the stator of the anode induction motor located?
a. inside the glass envelope but outside the rotor
b. outside the glass envelope and outside the rotor
c. inside the glass envelope and inside the rotor
d. outside the glass envelope but inside the rotor
ANS: B
DIF: Medium
4. The exposure switch on an x-ray machine is intended to ____.
a. initiate the exposure
b. terminate the exposure
c. both initiate and terminate the exposure
d. rotate the anode up to speed
ANS: A
DIF: Medium
5. The exposure switch is found between the ____.
a. incoming line and the circuit breaker
b. autotransformer and the timer circuit
c. exposure switch and the step-up transformer
d. incoming line and the step-down transformer
ANS: B
DIF: Medium
6. The electrical device used to adjust the mA selection is the ____.
a. autotransformer
c. switch
b. stator
d. variable resistor
ANS: D
DIF: Easy
7. The time control is found between the ____.
a. incoming line and the exposure switch
b. autotransformer and the timer circuit
c. exposure switch and the step-up transformer
d. incoming line and the step-down transformer
ANS: D
DIF: Medium
8. The mA control is found between the ____.
a. incoming line and the exposure switch
b. autotransformer and the timer circuit
c. exposure switch and the step-up transformer
d. incoming line and the step-down transformer
ANS: D
DIF: Medium
9. The kVp control is found between the ____.
a. incoming line and the exposure switch
b. autotransformer and the timer circuit
c. exposure switch and the step-up transformer
d. incoming line and the step-down transformer
ANS: A
DIF: Medium
10. Medical x-ray units can be classified as ____.
a. diagnostic
b. therapeutic
ANS: D
c. fluoroscopic
d. both a and b
DIF: Easy
11. The diagnostic x-ray range is approximately ____.
a. 10 to 1,200 mA
c. 25 to 150 kVp
b. 0.001 to 10 seconds
d. all of the above
ANS: D
DIF: Easy
12. The advantage of a curved top radiographic table is ____.
a. positioning accuracy in oblique and lateral positions
b. level support of the radiographic film
c. easy clean up
d. a smaller object image distance
ANS: D
DIF: Medium
13. The Bucky tray consists of ____.
a. a moving 14 × 17 inch grid
b. a stationary 14 × 17 inch grid
ANS: C
DIF: Medium
14. Radiographic table tops may be ____.
a. floating
b. stationary
ANS: D
c. a moving 17 × 17 inch grid
d. a stationary 17 × 17 inch grid
c. motor driven
d. all of the above
DIF: Medium
15. Radiographic rooms equipped with a tilting table are primarily designed for performing ____
procedures.
a. diagnostic
c. fluoroscopic
b. angiographic
d. both a and c
ANS: D
DIF: Easy
16. The height of the average radiographic table top to the floor is ____ inches.
a. 25
c. 60
b. 40
d. 120
ANS: B
DIF: Easy
17. Tube suspension systems include ____.
a. overhead
b. mobile
ANS: D
c. C-arm
d. all of the above
DIF: Medium
18. Which tube suspension system offers the greatest multidirectional movement?
a. overhead tube suspension system
c. floor tube suspension system
b. floor-to-ceiling tube suspension system
d. mobile tube suspension system
ANS: A
DIF: Medium
19. The incoming line current is supplied ____.
a.
b.
c.
d.
in the form of a three-phase power cycle
in the form of a single-phase power cycle
as a direct current
at approximately 60 volts
ANS: A
DIF: Easy
20. Nearly all x-ray equipment operates from an incoming line of ____.
a. 210 V
c. 120 Hz
b. 120 AC
d. 210 A
ANS: A
DIF: Easy
21. When full-wave rectification is applied to three-phase current, a ____ ripple is produced.
a. wye
c. voltage
b. star
d. delta
ANS: C
DIF: Medium
22. A three-phase, rectified current produces a voltage ripple of ____ pulses per Hz.
a. 3
c. 9
b. 6
d. 24
ANS: B
DIF: Medium
23. A star or delta connection is used to ____.
a. tap a single phase of power
b. combine three-phase current
ANS: B
c. produce rectification
d. drop the wave peak to zero
DIF: Medium
PROBLEM
1. What is the approximate rms voltage of a single-phase sine wave with a kVp of 65?
ANS:
45.9 kVp
DIF: Difficult
2. What is the approximate rms voltage of a single-phase sine wave with a kVp of 75?
ANS:
53.0 kVp
DIF: Difficult
3. What is the approximate rms voltage of a single-phase sine wave with a kVp of 80?
ANS:
56.6 kVp
DIF: Difficult