physics circuit
What term describes the process through which free electrons are created within the x-ray tube?
. Thermionic emission
Which components in the x-ray circuit must receive alternating current (AC) in order to function? 1. Autotransformer2. Step-up transformer3. Step-down transformer
1,2,&3
What is the secondary (output) voltage of the autotransformer when the assigned tube potential is 110 kVp?
110 V
In the absence of the autotransformer, the step-up and step-down transformers would be supplied with a continuous voltage of:
220 Volts
What is the voltage ripple within a 3-phase 12-pulse x-ray system?
4%
What is the secondary (output) voltage of the autotransformer when the assigned tube potential is 76 kVp?
76 V
Within a transformer, electromagnetic induction is the process through which:
A fluctuating magnetic field creates an electric current Electromagnetic induction is the process through which a magnetic field creates ("induces") current to flow. This occurs between the primary and secondary sides of a transformer. Alternating current on the primary side of the transformer creates a fluctuating magnetic field. This magnetic field interacts with the secondary coil of the transformer to create a new current. The new current will be higher or lower than the original current based on the turns ratio.
The rectification bridges within the x-ray circuit function to modify the electrical power within the x-ray system by converting:
Alternating current to direct current
A transformer is described as having a turns ratio of 40:1. How will this transformer change amperage?
Amperage will decrease
Which of the following statements describe the basic construction of an autotransformer within the x-ray circuit?
An iron core and a single wire coil
Which of the following statements describe the location of the autotransformer within the x-ray circuit?
Between the main power supply and the step-up transformer
Where are rectifiers positioned within the x-ray circuit?
Between the step-up transformer and the x-ray tube
Which aspect of the x-ray circuit protects the system from power surges and short-circuits?
Circuit breaker
The function of the rectifier(s) within the x-ray circuit is to:
Convert alternating current to direct current
Alternating current (AC) is best described as which of the following?
Current that alternates between positive and negative polarity
The type of rectifier used in modern x-ray equipment is called a
Diode
Converting a 3-phase unrectified current to 3-phase 6-pulse current requires which of the following devices?
Diodes
A transformer operates on the principle of
Electromagnetic induction A transformer operates on the principles of electromagnetic induction. There are no moving parts in a transformer. Instead, a fluctuating magnetic field is used to induce a new electrical current that has a different voltage than the original.
The amount of time the kilovoltage potential is applied to the x-ray tube is controlled by which of the following devices?
Exposure timer
What type of rectification has occurred when the negative polarity of an alternating waveform has been inverted so that all electrons within the waveform flow in the same direction?
Full-wave rectification
When all exposure factors are the same, what type of rectification will produce an x-ray beam with the greatest intensity?
Full-wave rectification
A waveform with large gaps between positive voltage peaks is a result of:
Half-wave rectification
In order to create sufficient heat within the cathode filament, the power supplied to the filament must be:
High amperage
In order to create a steady flow of highly penetrating x-rays, power arriving at the x-ray tube must be:
High-voltage direct current (DC)
Consider a transformer that has 10 times more turns on the secondary side than on the primary side. How will this transformer change the voltage?
Increase by a factor 10 The transformer described is a step-up transformer. The step-up transformer with 10x more wire turns on the secondary will increase voltage by a factor 10 (multiply by 10)
What is the function of the step-down transformer within the x-ray circuit?
Increase current
Which statement is true regarding the function of a step-up transformer? A step-up transformer:
Increases voltage and decreases amperage The function of a step-up transformer is to increase voltage and decrease amperage within the x-ray circuit. Transformers are named according to how they change the voltage. A step-up transformer increases voltage and step-down transformer decreases voltage.
What technical factor controls the temperature of the cathode filament within the x-ray tube?
Milliamperage (mA)
Failure of the rheostat within the x-ray circuit would result in the inability to:
Modify the filament current
Failure of the autotransformer within the x-ray circuit would result in an inability to:
Modify the x-ray tube voltage
The term "phase" in an x-ray circuit refers to the:
Number of distinct waveforms in the circuit
The turns ratio of a transformer is described as the:
Number of secondary coils to the number of primary coils The ratio of the number of secondary coils to primary coils describes the turns ratio. The difference between these coils is what determines the voltage change. If there are more turns on the secondary side the voltage will increase. If there are more turns on the primary side the voltage will decrease
Turns ratio of a transformer is defined as the ratio of the:
Number of turns on the secondary side to the number of turns on the primary side
Which of the following turns ratios are required for the autotransformer to STEP-UP the incoming line voltage?
Primary turns (NP) < Secondary turns (Ns)
Which of the following turns ratios are required for the autotransformer to STEP-DOWN the incoming line voltage?
Primary turns (NP) > Secondary turns (Ns)
Which component of the x-ray circuit ensures that electrons flow in only one direction through the x-ray tube?
Rectifiers
Where are rectifiers located within the x-ray circuit
Rectifiers are located in the secondary circuit
The filament current is controlled by the technologist through a device called a(n):
Rheostat
An autotransformer functions based on the principle of:
Self-induction
A transformer is constructed with 100 turns on the primary side and 10 turns on the secondary side. What type of transformer is this
Step-down transformer
A transformer with a greater number of wire turns on the primary side compared to the secondary side would be considered a(n):
Step-down transformer A step-down transformer has more turns in the primary coil than in the secondary. The voltage change is determined by the turns ratio or the ratio of secondary to primary turns. More turns in the secondary coil causes the voltage to increase.
What type of transformer must be used in the filament circuit in order for thermionic emission to be possible?
Step-down transformer A step-down transformer is required in the filament circuit to increase amperage to the level needed for thermionic emission. A step-down transformer works to decrease voltage and increase amperage.
Which type of transformer is needed for delivering high amperage to the filament circuit?
Step-down transformer A step-down transformer will cause amperage to increase and voltage to decrease. A step-down transformer must be used within the filament circuit to generate sufficient current for the process of thermionic emission.
A transformer having a turns ratio greater than one is described as a:
Step-up transformer
Which component of the x-ray circuit operates on the principle of mutual-induction?
Step-up transformer
Which type of transformer is incorporated within the high-voltage portion of the x-ray circuit?
Step-up transformer A step-up transformer is included within the high voltage section of the x-ray circuit in order to provide the needed voltage for x-ray production. This transformer converts electrical power from volts into kilovolts.
Failure of the step-up transformer within the x-ray circuit would result in an inability to:
Supply adequate voltage to the x-ray tube
Convert alternating current to direct current
The step-up transformer and the x-ray tube
An autotransformer is used to control which aspect of the x-ray circuit electrical supply?
Voltage (V)
The step-up transformer in the x-ray circuit serves to modify the current within the x-ray system by converting:
Volts to kilo-volts
What exposure setting directly affects the voltage change within the autotransformer?
kVp station
Which of the following devices is located within the filament circuit of the x-ray system?
mA selector