Deck 6: X-Ray Circuit and Tube Heat Management

Question 1

Which of the following components are located on the low-voltage side of the x-ray circuit?
1) kVp selector
2) Autotransformer
3) Step-up transformer

A) 1 only
B) 1 and 2 only
C) 2 and 3 only
D) 1, 2, and 3

Answer 1

1 and 2 only

Question 2

Which of the following are true concerning high-frequency (HF)generators,compared to 1-phase and 3-phase generators?
1) Produce x-rays more efficiently.
2) Require less exposure time.
3) Produce the greatest amount of x-rays for the same technique.

A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2, and 3

Answer 2

1, 2, and 3

Question 3

In which circuit is the step-up transformer located?

A) Incoming
B) Filament
C) Low-voltage
D) High-voltage

Answer 3

High-voltage

Question 4

Which of the following is the function of the autotransformer?
1) Provides the means for variable kVp selection
2) Provides compensation for fluctuations in the incoming line voltage
3) Supplies power to the other parts of the x-ray circuit

A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2, and 3

Question 5

The process of causing alternating (A-C)current to flow in one direction (D-C)only is called:

A) rectification.
B) induction.
C) grounding.
D) compensation.

Question 6

Which control on the x-ray generator is adjusted to heat the filament in the x-ray tube?

A) kVp
B) exposure timer
C) mA
D) AEC

Question 7

According to the following tube rating chart,what is the maximum exposure time obtainable at 90 kVp and 500 mA?

A) 2/10 sec
B) 1/10 sec
C) 1/20 sec
D) 1/30 sec

Question 8

To prolong x-ray tube life,the tubes should be operated at about ______ of capacity.

A) 80%
B) 50%
C) 10%
D) 100%

Question 9

The maximum heat capacity of the anode of the x-ray tube is rated in terms of:

A) volts.
B) ohms.
C) coulombs.
D) heat units.

Question 10

The purpose of a diode in an x-ray circuit is to:

A) vary the kilovoltage.
B) vary the milliamperage.
C) electrically convert A-C to D-C.
D) increase the 60 Hz frequency to 6,000 Hz.

Question 11

Into what three sections (subcircuits)is the x-ray circuit divided?

A) The step-up, the step-down, and the line voltage compensator
B) The low-voltage, filament, and high-voltage circuits
C) The production, induction, and safety circuits
D) The kVp meter, milliamp meter, and the exposure switch circuits

Question 12

Which of the following is the formula to calculate the heat produced by an exposure made on a three-phase generator?

A) mA × time (sec) × kVp
B) mA × time (sec) × 1.10
C) mA × time (sec) × 1.35
D) mA × time (sec) × 1.40

Question 13

Exposure times that are as low as 0.001 sec are typical of a(n):

A) mechanical timer.
B) synchronous (impulse) timer.
C) electronic timer.
D) phototimer.

Question 14

The power to the x-ray room that is supplied by the utility company is usually which of the following?

A) 220 V
B) 500 V
C) 80 kVp
D) 90 kVp

Question 15

The autotransformer is primarily used for:

A) variable kVp selection.
B) variable mA selection.
C) exposure time selection.
D) automatic exposure control.

Question 16

A series of warm-up exposures is made on a cold x-ray tube to:

A) heat the filament.
B) prevent damage to the anode from sudden heating.
C) bring the anode rotor up to speed.
D) check that the machine is working properly.

Question 17

Which of the following is located on the high-voltage side of the x-ray circuit?

A) Autotransformer
B) Step-down transformer
C) mA selector
D) X-ray tube

Question 18

Which of the following transformers reduces the voltage on the secondary side to provide an appropriate current to heat the filament?

A) Autotransformer
B) Step-down transformer
C) Step-up transformer
D) mA meter

Question 19

Which of the following is located on the low-voltage side of the x-ray circuit and functions to measure the voltage output from the autotransformer?

A) Exposure timer
B) Step-down transformer
C) Step-up transformer
D) Rectifier

Question 20

What is the purpose of the filament circuit?

A) Supplies the heat required by the x-ray tube filament for thermionic emission of electrons
B) Provides the incoming power to the x-ray tube
C) Varies and stabilizes the incoming power to the high-voltage side of the x-ray circuit
D) Varies the voltage to the primary side of the step-up transformer

Question 21

How many x-ray exposures should be made to warm up the x-ray tube?

A) 1
B) 2
C) 3
D) 4

Question 22

Which of the following are types of automatic exposure control (AEC)devices?
1) Phototimers
2) Ionization chambers
3) Synchronous tubes

A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2, and 3

Question 23

Which of the following x-ray generators produces the greatest amount of x-rays for the same exposure technique?

A) 1-phase
B) 3-phase, 6-pulse
C) 3-phase, 12-pulse
D) High-frequency

Question 24

Nearly all new x-ray machines manufactured today use ______ generators.

A) 1-phase
B) 3-phase, 6-pulse
C) 3-phase, 12-pulse
D) high-frequency

Question 25

Every x-ray exposure that is made will have what technical factors set on the control panel?
1) mA
2) kVp
3) Exposure time

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and 3

Question 26

X-ray exposure times that can be set on the generator can go up to as high as ____ sec.

A) 4
B) 5
C) 6
D) 8

Question 27

What electrical system and device terminates the exposure time after an exact amount of radiation for a given body part has been detected?

A) Synchronous exposure control
B) Electronic exposure control
C) Automatic exposure control
D) Milliamperage control

Question 28

Which of the following must be absolutely accurate when using AEC for exposure technique?

A) Setting the central ray
B) Patient positioning
C) Collimation size
D) Determining the correct kVp

Question 29

Public Law 90-602 states that generators must terminate the exposure time at what mAs?

A) 300 mAs
B) 500 mAs
C) 600 mAs
D) 2000 mAs

Question 30

Which of the following x-ray generators will produce the greatest amount of heat for the same exposure technique?

A) 1-phase
B) 3-phase
C) 3-phase, 12-pulse
D) High-frequency

Question 31

In a high-frequency generator,the incoming 60 Hz electrical frequency is raised to what level?

A) 2,500 Hz
B) 5,000 Hz
C) 6,000 Hz
D) 8,000 Hz

Question 32

For which exposure technique system would a technique chart not be necessary?

A) Density control
B) AEC
C) APR
D) Manual techniques

Question 33

Which of the following devices on the x-ray generator will enable the operator to override the AEC system when an exposure is overexposed or underexposed?

A) kVp control
B) Density control
C) Back-up timer
D) Detector selection control

Question 34

When using APR to set the exposure technique,which of the following will be automatically selected with the simple push of a button?
1) mA
2) kVp
3) Grid

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and 3

Question 35

Which type of exposure timer is capable of shorter exposure times (1 msec or less)?

A) Synchronous timer
B) Electronic timer
C) Manual timer
D) Back-up timer

Question 36

When using automatic exposure control (AEC)for setting exposure techniques,which technical factor does not have to be set?

A) mA
B) mAs
C) kVp
D) Exposure time

Question 37

If the automatic exposure system fails during an exposure,which built-in control will terminate the exposure?

A) Back-up timer
B) kVp circuit breaker
C) Filament circuit breaker
D) Timer circuit breaker

Question 38

How many detectors are built in to the AEC system and can be activated to determine the exposure technique?

A) 1
B) 2
C) 3
D) 4

Question 39

Some x-ray generators are programmable and the exposure factors from the technique chart can be programmed into the generator. This system is called:

A) manual exposure control.
B) programmed exposure control.
C) automatic exposure control (AEC).
D) anatomically programmed radiography (APR).

Question 40

What type of circuit in a high-frequency generator brings the x-ray frequency up to the very high level needed to produce x-rays?

A) Inverter circuit
B) AEC circuit
C) APR circuit
D) High-voltage circuit

Question 41

Which of the following would be considered good practice for maintaining x-ray tube life?
1) Use the high-speed rotor.
2) Use low mA settings whenever possible.
3) Do not hold down the rotor switch for long periods.

A) 1 and 2
B) 1 and 3
C) 2 and 3
D) 1, 2, and 3

Question 42

The x-ray tube capacity for a single exposure can be determined by consulting the:

A) tube rating chart.
B) generator manual.
C) kVp maximum setting.
D) mA maximum setting.