Chapter 5
Percentage of three phase, 6 pulse
13%
Most X-ray systems operate on:
220 V power
440 volts is supplied to 1000 primary turns of an auto transformer. If the desired output voltage is 100 V how many secondary turns must be tapped?
227
Filaments operate at a current of _____ A
3-6 A
A filament current of 5 A is necessary for thermionic emission. What electron flow is this?
3.2 x 10 to the 19
Percentage of 3 phase, 12 pulse:
4%
220 V is supplied to 800 primary turns of an autotransformer. What will be the output voltage across 200 secondary turns?
55 V
To generate three phase 6 pulse power at least how many rectifiers are necessary:
6
Percentage of full wave rectifued
71%
The main advantage of full wave rectification over half wave rectification is:
A greater number of x-rays per cycle
In the design of an auto transformer:
A single coil serves as both the primary and secondary coils
Unrectified voltage
Across an x-ray tube would cause it to act like a diode, conducting electricity in only one direction
The principal purpose of the auto transformer is to:
Adjust voltage
Transformers only operate on _____ current
Alternating (AC)
Equation Watts=
Amperes X volts
Xray tables are most made of:
Carbon fiber
A rectifier:
Changes AC to DC
The auto transformer has only one:
Coil
Space charge:
Collection of electrons around filament
Which of the following would be correct to use for expressing X-ray tube current?
Coulombs/second
Equation Power=
Current X potential
Power rating=
Current X potential
The auto transformer can be used to do which of the following?
Increase kVp
Which of the following is an advantage of three phase power over single phase power?
Increased x-ray intensity per mAs
Semi conductor rectifier:
Is a solid state device
N-type:
Loosely bound electrons are free to move
kVp meter:
Measures voltage output from the autotransformer.
In half with rectification each inverse half cycle in the primary circuit corresponds to how many voltage pulses across the x-ray tube?
One
Autotransformer:
Power supply to the x-ray imaging system
Which of the following is used to determine the voltage before exposure?
Pretending voltmeter
Electeomagnetic or electric motive force:
Production of electrical conductor in a changing magnetic field
The output voltage from the auto transformer is;
Proportional to the turns ratio
We want the table to be:
Radiolucent
Secondary side is a:
Step up transformer
Radiation quantity:
The amount of energy transferred
primary voltage / secondary voltage
Voltage it receives/ voltage it provides
Which of the following is higher for a single phase high voltage generator that for a three phase high-voltage generator?
Voltage ripple
Line compensation:
is required to stabilize voltage
The disadvantage of a self rectified circuit is:
its limited exposure time
Which of the following is directly connected to the auto transformer?
kVp meter
Power rating is expressed in what unit.
kilowatt
X-ray tube current crossing from cathode to anode is measured in:
mA
line compensator:
measures the voltage provided to the x-ray imaging system and adjusts that voltage to precisely 220 V
X-ray tube current is usually measured in which of the following?
milliamperes (mA)
the control of exposure time is always:
on the primary side of the high voltage transformer
Full wave rectification:
requires at least four rectifiers
Power to the primary side of the high voltage transformer comes from the:
secondary side of the autotransformer
The filament transformer is usually:
step-down transformer
high voltage transformer:
step-up transformer
Full wave rectification
the conversion of the opposing half of the incoming electron flow to always move in the same direction, instead of discarding half the cycle
Concerning the transformers used in x-ray circuit:
the high voltage transformer is a step up device
The filament transformer is a ________ transformer.
to step down
Selection of kVp:
uses the step up transformer
Percentage of high frequency:
1%
Percentage of self rectified:
100%
The voltage ripple associated with the various x-ray generators is:
100% for self rectification
A change in voltage waveform from the primary side to the secondary side of the high-voltage transformer produces a change in;
amplitude
Only difference between the primary and secondary waveforms is their:
amplitude
Diode:
an electronic device that contains two electrodes
The filament circuit:
begins at the autotransformer and ends at the filament
The unit mAs:
could be expressed in coulombs
step-down transformer
decreases voltage
Radiation quality:
determines degree of penetration and the amount of energy transferred
Which of the following is contained in a typical high-voltage generator?
diode rectifiers
Oil is used in the high-voltage section of an x-ray imaging system for which of the following functions:
electrical insulation
P-type:
has a "hole" or is missing electron
The voltage supplied to an x-ray imaging system is 220 V the voltage used by the x-ray tube is produced by which of the following?
high voltage transformer
Which of the following is a disadvantage of three phase power compared with single phase power?
higher capital cost
The principal purpose of the high-voltage transformer is to do which of the following?
increase voltage
The filament transformer:
increases current
step-up transformer:
increases voltage
Rectifier:
Device which allows current to flow in only one direction
The auto transformer converts:
Electric energy to electric energy
Falling load generator:
Exposure begins at maximum mA and the mA drops as the anode heats
The autotransformer operates on the principle of:
Faraday's Law
Temperature is controlled by the:
Filament
Exposure technique of 100 mA at 100 ms compared with 50 mA at 50 ms results in:
Four times the total number of electrons
Which of the following principles of boulder to rectification produces the maximum efficiency of x-ray production:
High frequency generator
space charge effect:
a correction circuit has to be incorporated to counteract the
Half-wave rectification
a method of converting alternating to direct current in which half of the current is lost
Operating console:
allows the technologist to control the x-ray tube current and voltage