1.
The most common device used to create the high potential difference (kilovoltage) across the x-ray tube is the high tension:
Correct Answer
D. Transformer
Explanation
A transformer is the most common device used to create the high potential difference (kilovoltage) across the x-ray tube. A transformer works by changing the voltage of an alternating current (AC) by electromagnetic induction. It consists of two coils, a primary coil and a secondary coil, which are wound around a common magnetic core. The primary coil is connected to the power source, while the secondary coil is connected to the x-ray tube. The transformer steps up the voltage from the power source to create the high potential difference required for generating x-rays.
2.
The current passing between the secondary of the high tension transformer and the rectifiers is best described as a type of:
Correct Answer
A. High voltage (kV) AC
Explanation
The current passing between the secondary of the high tension transformer and the rectifiers is best described as high voltage (kV) AC because it is coming from the secondary of a high tension transformer, which typically produces high voltage alternating current.
3.
A single diode in a circuit having an A.C. power source will produce a ______wave rectified signal.
Correct Answer
B. Single –pHase half
Explanation
When a single diode is used in a circuit with an AC power source, it will produce a single-phase half-wave rectified signal. This means that only half of the AC waveform will be rectified and converted into a DC signal, while the other half will be blocked by the diode. This type of rectification is commonly used in applications where only a positive or negative half of the waveform is required, such as in certain power supplies or audio amplifiers.
4.
The part of the x-ray generator that supplies the high voltage necessary between the cathode and the anode is called the:
Correct Answer
B. Main x-ray circuit
Explanation
The main x-ray circuit is responsible for supplying the high voltage needed between the cathode and the anode in an x-ray generator. It is the primary circuit that controls the generation and production of x-rays. The filament circuit, on the other hand, is responsible for heating the filament to produce the electrons needed for x-ray production. The low voltage circuit is responsible for controlling the low voltage components of the generator, while the thermionic emission circuit is related to the process of electron emission from the filament.
5.
Three-phase, full wave rectified A.C. has ________peaks in a single cycle.
Correct Answer
B. 6
Explanation
In a three-phase, full wave rectified A.C., there are six peaks in a single cycle. This is because a full wave rectification process converts both the positive and negative halves of the A.C. waveform into positive halves. In a single cycle, there are two positive peaks and two negative peaks, resulting in a total of six peaks.
6.
The type of unit most likely to possess the smallest voltage ripple is a :
Correct Answer
D. High frequency unit
Explanation
A high frequency unit is most likely to possess the smallest voltage ripple because it operates at a higher frequency, which allows for faster switching and smoother voltage transitions. This means that there is less variation or fluctuation in the voltage output, resulting in a smaller voltage ripple. In contrast, full wave single-phase units, 3-phase 6 pulse units, and self-rectified units may have larger voltage ripples due to their lower operating frequencies and slower switching speeds.
7.
In a stationary anode tube, the target is imbedded in an anode made of:
Correct Answer
C. Copper
Explanation
In a stationary anode tube, the target is embedded in an anode made of copper. Copper is a commonly used material for stationary anodes due to its high thermal conductivity and good heat dissipation properties. These properties allow the anode to efficiently absorb and dissipate the heat generated during the X-ray production process. Additionally, copper is a relatively cost-effective material compared to other options like tungsten, molybdenum, or rhenium, making it a practical choice for stationary anode tubes.
8.
The anode of a modern rotating anode tube is generally composed of tungsten and:
1. Copper 2. Rhenium 3. Molybdenum
Correct Answer
C. 2 & 3
Explanation
The anode of a modern rotating anode tube is generally composed of tungsten, copper, rhenium, and molybdenum. The correct answer states that the anode is composed of rhenium and molybdenum, which is consistent with the information given.
9.
Tube support systems available for use in modern diagnostic imaging equipment include;
Correct Answer
E. A, B, and C
Explanation
The correct answer is A, B, and C. Tube support systems available for use in modern diagnostic imaging equipment include overhead ceiling support versions, floor-to-ceiling support versions, and C-arm support versions. This means that there are multiple options for supporting the tube in different configurations depending on the specific needs and setup of the imaging equipment.
10.
Which of the following is an advantage that a rotating anode tube will have over a stationary anode tube?
1. Increased heat dissipation
2. Higher tube ratings
3. Reduced roughing of the target
Correct Answer
D. 1,2, and 3
Explanation
A rotating anode tube has several advantages over a stationary anode tube. Firstly, it allows for increased heat dissipation as the rotating anode allows for more surface area to be exposed to the cooling system, preventing overheating. Secondly, a rotating anode tube can handle higher tube ratings, meaning it can handle higher levels of radiation without being damaged. Lastly, the rotating anode reduces roughing of the target, which prolongs the lifespan of the tube and reduces the need for frequent replacements. Therefore, the correct answer is 1, 2, and 3.
11.
The majority of heat in a modern rotating anode tube is dissipated through the:
Correct Answer
C. Passage of radiant heat to the tube envelope
Explanation
In a modern rotating anode tube, the majority of heat is dissipated through the passage of radiant heat to the tube envelope. This means that the heat generated during operation is transferred from the anode to the surrounding tube envelope through radiation. This method allows for efficient cooling of the anode and prevents overheating. Conduction of heat through the stem of the anode, transfer of the space charge to the anode disk, and absorption of electrons by the io sink are not the primary methods of heat dissipation in a modern rotating anode tube.
12.
Which of the following is used to focus the high speed electron stream toward the target of the anode?
Correct Answer
B. Nickel focusing cup
Explanation
The nickel focusing cup is used to focus the high-speed electron stream toward the target of the anode. This cup is made of nickel because it has good thermal conductivity and can withstand high temperatures. The cup is designed in a way that it shapes and directs the electron beam, ensuring that it hits the target accurately and efficiently. The use of the nickel focusing cup helps to optimize the performance and precision of the electron stream in various applications, such as electron microscopy and electron beam welding.
13.
In modern x-ray equipment, the device most often used for current rectifications is a(an):
Correct Answer
C. Solid state diode
Explanation
A solid-state diode is the most commonly used device for current rectification in modern x-ray equipment. A diode is a semiconductor device that allows current to flow in only one direction. It is used to convert alternating current (AC) into direct current (DC) by blocking the negative half of the AC waveform. This is important in x-ray equipment as it ensures that the x-ray tube receives a steady and consistent flow of current. Solid-state diodes are preferred over other options like modified x-ray tubes, thermionic valve tubes, or ionization chambers due to their reliability, efficiency, and compact size.
14.
The selection of voltage to the high tension transformer is most commonly made by adjusting the:
Correct Answer
D. Autotransformer
Explanation
The selection of voltage to the high tension transformer is most commonly made by adjusting the autotransformer. An autotransformer is a type of transformer that has a single winding and is able to step up or step down the voltage. It is commonly used to adjust the voltage in electrical systems. In this case, the autotransformer would be used to select the appropriate voltage for the high tension transformer, ensuring that the correct voltage is supplied to the transformer for optimal performance.
15.
The high amperage necessary to cause thermionic emission in the filament circuit is developed from the use of a:
Correct Answer
B. Step-down transformer
Explanation
A step-down transformer is used to decrease the voltage from the power source to a lower level, while increasing the current. In the case of the filament circuit, a high amperage is required to cause thermionic emission, which is the release of electrons from the filament. Therefore, a step-down transformer would be necessary to provide the high amperage needed for this process.
16.
The type of meter that is used to measure the current (tube current) between the electrodes of an x-ray tube is the:
Correct Answer
C. Milammeter –seconds meter
Explanation
The correct answer is Milammeter-seconds meter. A Milammeter-seconds meter is used to measure the current (tube current) between the electrodes of an x-ray tube. This type of meter is specifically designed to measure the current in milammeter-seconds, which is a unit used to quantify the amount of x-ray radiation produced. It is important to accurately measure the current in an x-ray tube to ensure proper radiation exposure and patient safety.
17.
The control for the amount of filament current in most modern radiographic units is directly related to the:
Correct Answer
C. Millampere slection
Explanation
The control for the amount of filament current in most modern radiographic units is directly related to the millampere selection. Millampere selection determines the amount of current flowing through the filament, which in turn affects the production of X-rays. By adjusting the millampere setting, the radiographer can control the intensity of the X-ray beam and therefore the exposure of the image receptor.
18.
Most x-ray machines used in the United States are designed to operate on a 220 volt or 440 volt:
Correct Answer
A. 60 hertz, alternating current power supply
Explanation
Most x-ray machines used in the United States are designed to operate on a 60 hertz, alternating current power supply. This is because the standard power supply in the United States operates at 60 hertz, which means the current alternates its direction 60 times per second. X-ray machines require a steady and consistent power supply to operate effectively, and the 60 hertz alternating current provides the necessary stability for the machine to function properly.
19.
The pre-reading kV meter measures the ____________on the secondary side of the autotransformer:
Correct Answer
D. Voltage
Explanation
The pre-reading kV meter measures the voltage on the secondary side of the autotransformer. This means that it is used to measure the electrical potential difference in the circuit. The kV meter is specifically designed to measure the kilovoltage, which is a unit of measurement for voltage. By measuring the voltage, the kV meter provides important information about the electrical characteristics of the circuit, allowing for accurate adjustments and monitoring of the electrical system.
20.
A transformer with more secondary windings than primary windings:
Correct Answer
A. Has a greater secondary voltage
Explanation
A transformer with more secondary windings than primary windings has a greater secondary voltage because the voltage is directly proportional to the number of windings. As the number of secondary windings increases, the voltage output also increases. This type of transformer is known as a step-up transformer because it steps up the voltage from the primary to the secondary side. Therefore, the correct answer is "Has a greater secondary voltage."
21.
The process by which alternating current is converted into pulsating direct current is termed:
Correct Answer
A. Rectification
Explanation
Rectification is the process of converting alternating current (AC) into pulsating direct current (DC). This is achieved by using a rectifier, which allows current to flow in only one direction. During rectification, the negative half-cycles of the AC waveform are inverted to positive half-cycles, resulting in a pulsating DC output. This process is commonly used in power supplies and electronic devices that require a steady DC power source. Polarization refers to the separation of positive and negative charges in an object, depolarization is the reversal of polarization, and electrification refers to the process of charging an object with electricity.
22.
3-phase current consists of three single-phase voltage wave forms separated by:
Correct Answer
C. 120 degrees
Explanation
In a 3-phase current system, the three single-phase voltage waveforms are separated by 120 degrees. This means that each waveform is offset from the other two by 120 degrees. This phase separation ensures that the three phases are evenly distributed over time, resulting in a balanced and efficient distribution of power.
23.
Four diodes can be used in a circuit having an A.C. power source to produce a ______wave rectified signal.
Correct Answer
D. Single-pHase, full
Explanation
When four diodes are used in a circuit with an AC power source, they can produce a single-phase, full wave rectified signal. This means that the entire AC waveform is converted into a DC waveform, with both the positive and negative halves of the AC cycle being rectified. The four diodes are arranged in a bridge configuration, known as a full wave bridge rectifier, which allows for the conversion of both positive and negative cycles of the AC input.
24.
The turns ratio of a(an) _______can be varied by selecting the number of turns between connections on a single coil
Correct Answer
B. Autotransformer
Explanation
An autotransformer is a type of transformer where the primary and secondary windings are connected together. By selecting the number of turns between connections on a single coil, the turns ratio of an autotransformer can be varied. This allows for the transformation of voltage levels, either stepping up or stepping down the voltage, depending on the application. Autotransformers are commonly used in various electrical systems to efficiently adjust voltage levels.
25.
To raise the voltage higher (kvP range) than the autotransformer is capable of raising it, a ____transformer is included in the tube circuit (Main x-ray circuit).
Correct Answer
A. Step-up
Explanation
To raise the voltage higher than what the autotransformer is capable of, a step-up transformer is included in the tube circuit. A step-up transformer has more turns in the secondary coil compared to the primary coil, which allows it to increase the voltage. This is necessary in the main x-ray circuit to provide the high voltage required for generating x-rays.
26.
The autotransformer is connected to the_____side of the step-up transformer
Correct Answer
A. Primary
Explanation
The autotransformer is connected to the primary side of the step-up transformer. This is because the autotransformer is used to adjust the voltage level before it enters the step-up transformer. By connecting it to the primary side, the autotransformer can effectively regulate the voltage and provide the necessary step-up transformation.
27.
An x-ray tube operates most efficiently with the ___, but the autotransformer and step-up transformer require ___.
Correct Answer
A. D.C. / A.C.
Explanation
An x-ray tube operates most efficiently with direct current (D.C.), as it provides a constant and smooth flow of electrons. On the other hand, the autotransformer and step-up transformer require alternating current (A.C.) to function properly. This is because A.C. can be easily transformed to different voltages using transformers, which is essential for adjusting the voltage to the desired level in the x-ray machine. Therefore, the x-ray tube and transformers have different requirements in terms of the type of current they operate with.
28.
A __________is a device that allows current to flow in one direction only.
Correct Answer
C. Diode
Explanation
A diode is a device that allows current to flow in one direction only. It acts as a one-way valve for electric current, allowing it to pass through in one direction while blocking it in the opposite direction. This characteristic is achieved through the use of a p-n junction, which creates a barrier that prevents the flow of current in the reverse direction. Diodes are commonly used in electronic circuits to control the flow of electricity and to convert alternating current (AC) to direct current (DC).
29.
The main power line in a hospital is usually a ______ volt, ______hertz A.C. source.
Correct Answer
A. 220 / 60
Explanation
The main power line in a hospital is usually a 220 volt, 60 hertz A.C. source. This is because most electrical equipment in hospitals is designed to operate on this standard voltage and frequency. The 220 volt supply is sufficient to power the various medical devices and equipment, while the 60 hertz frequency ensures smooth and stable operation of the electrical system.
30.
The filament circuit contains a ______transformer.
Correct Answer
B. Step-down
Explanation
The correct answer is step-down. A step-down transformer is used in a filament circuit to reduce the voltage from the power source to a lower voltage suitable for the filament. This is necessary because the filament requires a lower voltage to operate efficiently and prevent overheating. By stepping down the voltage, the transformer ensures that the filament receives the appropriate level of power for its operation.
31.
In a step-up transformer, the voltage is ________on the secondary side than on the primary.
Correct Answer
B. Higher
Explanation
In a step-up transformer, the voltage on the secondary side is higher than on the primary. This is because a step-up transformer is designed to increase the voltage from the input to the output. It does this by having more turns in the secondary coil compared to the primary coil, which results in a higher voltage output. This higher voltage is useful in applications where a higher voltage is required, such as in power transmission or in certain electronic devices.
32.
A line voltage compensator is incorporated into the primary circuit of a modern radiographic unit to:
Correct Answer
D. Maintain a constant kVp level
Explanation
A line voltage compensator is used in a modern radiographic unit to maintain a constant kVp (kilovolt peak) level. The kVp level is the maximum voltage applied across the X-ray tube during an exposure. By compensating for variations in the line voltage, the compensator ensures that the kVp level remains constant, which is important for achieving consistent and accurate X-ray images. This helps to minimize variations in image quality and exposure dose, ensuring that the X-ray unit produces reliable and consistent results.
33.
The high-tension portion of a modern x-ray circuit contains all of the following components EXCEPT:
Correct Answer
B. The filament selector
Explanation
The high-tension portion of a modern x-ray circuit contains the x-ray tube cables, solid state diodes, and the millammeter. The filament selector is not part of the high-tension portion.
34.
Which of the following changes would be associated with a higher amount of current passing through the filament of the x-ray tube?
Correct Answer
B. The selection of a higher mA station
Explanation
The selection of a higher mA station would be associated with a higher amount of current passing through the filament of the x-ray tube. mA (milliamperes) is a measure of the current flowing through the filament, and a higher mA setting means a higher current. This increased current would result in more electrons being boiled off from the filament, leading to a higher amount of current passing through the x-ray tube.
35.
The high tension (step-up) transformer of a modern x-ray circuit is most closely related to the:
Correct Answer
B. High potential required to accelerate the electrons across the tube
Explanation
The high tension (step-up) transformer is responsible for increasing the voltage in the x-ray circuit. This high potential is necessary to accelerate the electrons across the tube, which is essential for the production of x-rays. The high voltage helps to overcome the resistance and create a strong electric field, allowing the electrons to gain the necessary energy to produce x-rays. Therefore, the high tension transformer is closely related to the high potential required to accelerate the electrons across the tube.
36.
Which of the following components are likely to be found in the primary circuit of a modern x-ray unit?
1. Autotransformer 2. Timer switch 3. The anode of the x-ray tube
Correct Answer
A. 1 and 2
Explanation
In a modern x-ray unit, the primary circuit is responsible for controlling the flow of electricity to the x-ray tube. The autotransformer is a component commonly found in the primary circuit, as it is used to regulate the voltage supplied to the x-ray tube. The timer switch is also likely to be found in the primary circuit, as it is used to control the duration of the x-ray exposure. The anode of the x-ray tube, however, is not a component of the primary circuit, but rather a part of the x-ray tube itself. Therefore, the correct answer is 1 and 2.
37.
The majority of components in a modern x-ray circuit are found in the primary circuit. This is done to:
Correct Answer
A. Reduce the risk from electrical shock
Explanation
The majority of components in a modern x-ray circuit are found in the primary circuit in order to reduce the risk from electrical shock. By keeping most of the components in the primary circuit, the chances of accidental contact with high voltage components in the secondary circuit are minimized. This helps to ensure the safety of both the operator and the patient during x-ray procedures.
38.
In nearly all radiographic units, the high-tension transformer is located in an oil filled tank that also houses the:
1. Rectifiers 2. Filament transformer 3. Autotransformer
Correct Answer
A. 1 and 2
Explanation
In nearly all radiographic units, the high-tension transformer is located in an oil filled tank. This tank also houses the rectifiers, which are responsible for converting the alternating current (AC) from the power source into direct current (DC) that can be used by the X-ray tube. Additionally, the tank also houses the filament transformer, which provides the necessary voltage to heat the filament in the X-ray tube. Therefore, the correct answer is 1 and 2.
39.
All of the following are advantages of a 3-phase power supply in a modern radiographic unit EXCEPT:
Correct Answer
C. Reduced scatter production
Explanation
A 3-phase power supply in a modern radiographic unit offers advantages such as shorter permitted exposures, higher beam quality, and higher beam intensity. However, it does not directly contribute to reduced scatter production. Scatter production is primarily influenced by factors such as the type of material being radiographed, the size of the field, and the energy of the X-ray beam. While a 3-phase power supply may indirectly affect scatter production by providing a more stable and consistent power source, it is not a direct advantage of this type of power supply.
40.
In a 3-phase, 12 pulse unit, rectification is accomplished by employing:
Correct Answer
C. 12 solid state diodes
Explanation
In a 3-phase, 12 pulse unit, rectification is accomplished by employing 12 solid state diodes. In this configuration, each phase of the 3-phase system is split into two, resulting in a total of 6 phases. Each phase is then rectified using two diodes, resulting in a total of 12 diodes. This allows for efficient and controlled rectification of the AC input voltage, ensuring smooth and stable DC output. The use of solid state diodes also offers advantages such as faster switching speeds, higher efficiency, and better reliability compared to thermionic diodes.