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Unit II- The X-Ray Circuit Exam Review
2023 - 2024 Questions With Complete Solution
*Nature of Electricity
- is the study of stationary electric charges
- is the study of charges in motion and is often considered "electricity" - ANS-1. electrostatics
- electrodynamics
-Electric Charge
- Is a property of __
- Smallest unit of charges are the: 2
- Si measurement of charge is the __: and it equals __
- Conductivity increases with an __ in the number of free electrons in an atom - ANS-1. matter
- proton, electron
- coulomb;6.25 X 10^18 electrons
- increase
*Nature of Electricity
- __ increases with an increase in free electrons
- Conductors: 3
- Insulators: 3 - ANS-1. conductivity
- copper, gold, aluminum
- plastic, glass, and rubber
*Five General Principals of Electrostatics
- Like charges __ and unlike charges __
- The electrostatic charges between two charges is __ to the product of their quantities and __ to the square of the distance between them(aka coulombs law)
- Electric charges reside only on the __ of a conductor
- The concentration of charges on a curved surface of a conductor is __ where the curvature is greatest
- Only __ are free to move in solid conductors - ANS-1. repel, attract
- directly proportional, indirectly proportional
- external surface
- greatest
- negative charges(electrons)
*Electrification of Charges
- electrons are transferred from one object to another by rubbing two objects together
- electrons are transferred from a charged object to a conductor by touching together
- process by which an uncharged metallic object experiences a shift of electrons when brought into electric field of a charged object - ANS-1. friction
- contact
- induction
*Electric Potential
- In order for electricity to flow, a __ must exist
- is the ability to do work because of separation of charges
- Electrons follow the path of __ - ANS-1. potential difference
- electric potential
- least resistance
- a type of current that flows in only one direction - ANS-1. indirect current
- direct current
Resistance is measured in __ after Georg Simon Ohm who discovered the __ relationship between current and resistance; Ohms Law= - ANS-ohms, inverse, V=IR
4 factors affecting resistance - ANS-1. material
- length
- cross-sectional area
- temperature
- fewer electrons in this the more resistance
- Longer increases resistance
- smaller area increases resistance
- with metallic conductors, the resistance becomes greater as the __ of the conductor rises - ANS-1. material
- length
- cross-sectional area
- temperature
*Conductors, Insulators, and Electronic Devices
- __ are those materials with an abundance of free electrons that allow a relatively free flow of electricity, whereas __ have virtually no free electrons and are therefore very poor conductors of electricity
- __ have loosly bound electrons
- __ have tightly bound electrons - ANS-1. conductors, insulators
- conductors
- insulators
__ is a closed pathway through which electricity may flow - ANS-electric current
STUDY PICTURE FLASHCARDS - ANS-
*Conductors, Insulators, and Electronic Devices
- opens circuit
- temporarily store an electric charge
- increases or decreases voltage
- provide electrons through a chemical reaction; store an electric charge long term; provide electric potential - ANS-1. switch
- capacitors
- transformer
- batteries
STEP DOWN TRANSFORMER: __ VOLTAGE; __ AMPERAGE - ANS-lower, higher
*Conductors, Insulators, and Electronic Devices
- inhibit flow of electrons, regulate the flow of electricity in area and it is placed
- an adjustable or variable form of resistor
- allow electrons to flow in only one direction
- break circuit if there is a sudden surge of electricity - ANS-1. resistors
- rheostat
- diodes
- protective devices
- Magnetic fields are distorted by __ and unaffected by __ - ANS-1. flux
- south to north pole, north to south pole
- repel, attract
- magnetic materials, nonmagnetic materials
-Three Laws of Magnetism that promotes the Understanding of Electromagnetism
- Every magnet has a __ and __
- Like poles __ each other and unlike poles __ each other
- The force of attraction or repulsion varies directly with the __ of the poles and inversely with the __ between them - ANS-1. north and south pole
- repel, attract
- strength, square of distance
*Electromagnetism and Electromagnetic Induction
- The magnetic field is measured in the SI unit __
- MRI units in medical imaging use magnetic strengths from __ to __ - ANS-1. Telsa
- .5-5T
*Magnetic Properties
4 classifications - ANS-nonmagnetic materials
diamagnetic materials
paramagneti materials
ferromagnetic materials
*Magnetic Properties
- are not attracted to magnetic fields at all
- are weakly repelled by magnetic fields
- are weakly attracted by a magnetic fields
- are strongly attracted to magnetic fields - ANS-1. nonmagnetic materials
- diamagnetic materials
- paramagnetic materials
- ferromagnetic materials
__ and __ are two parts of the same basic force. That is any flow of electrons is surrounded by a __. Likewise, a moving magnetic field can create an __ - ANS-electricity and magnetism, magnetic field, electric current
*Electromagnetism and Electromagnetic
-Danish Physicist Hans Oersted
- Discovered a compass needle is deflected when placed near a __ carrying an __
- Later discovered that a __ with an __ can intensify - ANS-1. conductor, electric current
- solenoid(coiled wire), iron core
*Electronmagnetism and Electromagnetic Induction
-British Scientist Michael Faraday
- Discovered that moving a conductor through a __ induces an __ in that conductor
- This phenomenon is called __ current may be induced to flow in a conductor by moving that conductor through a __ or by placing the conductor in a moving __ - ANS-1. magnetic field, electric current
- electromagnetic induction, , magnetic field, magnetic field
*Two types of Electromagnetic Induction - ANS-1. mutual induction
- self induction
*General Xray Circuit
Three sections of the xray circuit include: - ANS-1. primary circuit
- secondary circuit
- filament circuit
Transformers regulate __ - ANS-kVp
*Primary Circuit
Consists of: 5 - ANS-1. main power switch
- circuit breaker
- autotransformer
- timer circuit
- primary side of step up transformer
*Primary Circuit
-Main Power Switch
- Is simply __ or __ for unit and is connected to the __ to the facility
- A line compensator regulates the inconsistent supply of __
- The device is wired into an __ which automatically adjusts the power supply as close to __ as possible
- __ are used to protect against short circuits and electrical shock
- The __
- The radiographer controls the autotransformer through the __ on the operating console, and directly determines the voltage applied to the xray tube to produce xrays - ANS-1.on, off, main power supply
- 220 volts
- autotransformer, 220 volts
- circuit breakers
- autotransformer
- kVp
*Primary Circuit
-Timer Circuit
- based on a synchronous motor designed to turn a shaft at 60 revolutions per second or 3600 per minute
- most widely used today; once the capacitor receives a programmed amt of charge it terminates the exposure; the amt it takes to reach this charge is controlled by a variable resistor - ANS-1. synochornous timer
- electronic timer
*Primary Circuit
-Automatic Exposure Control
- AEC controls the __ of radiation reaching the image receptor and therefore has no effect on other __ such as contrast. THe radiographer must still select the __ and in many cases the __
- The AEC is a device that serves to __. It consist of an __ that is place between the image receptor and the pt. As the radiation exits pt and passes through the ionization chamber, a signal is sent to __. The __ and __ of the body part becomes the timer variable - ANS-1. quanitity, image characteristics, kVp, mA
- terminate exposure, ionization chamber, terminator exposure, thickness, density
*Primary Circuit
-Step-Up Transformer
- Is used to __ voltage from the __ to kVp necessary for xray production
- Primary side of the step up transformer is on the __ of the circuit - ANS-1. increase, autotransformer
- primary side
*Secondary Circuit
- mA x sec=
- The step down transformer __ voltage but __ amperage
- A __ encourages the boiling off of electrons at the filament which __ the number of electrons send to the anode to produce xray photons - ANS-1. rheostat
- mAs
- reduces, increases
- high amperage, increases
*Filament Circuit
The __ is the final part of the filament circuit. There are typically __ and __ in the xray tube. - ANS- filament, small and large
*Filament Circuit
A __ and __ at the __ side where electrons are boiled off and driven to the __ side by a very high voltage supplied by the secondary circuit - ANS-small and large filament, cathode, anode
