Home
Subjects
Explanations
Create
Study sets, textbooks, questions
Log in
Sign up
Upgrade to remove ads
Only $35.99/year
Principles of radiographic imaging chapter 3
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
Terms in this set (77)
extremely high-energy electricity produces high speed electrons that interact with matter
X rays are produced when:
equal
The positive and negatives charges of the protons and electrons are ____ in strength.
Electrostatics
the study of the distribution of fixed charges, or electrons at rest
the relationship between two objects, not their true atomic charges
When discussing electricity, the terms negative and positive refer to:
1. Repulsion-attraction
2. Inverse Square Law
3. Distribution
4. Concentration
5. Movement
List the five laws of electrostatics:
Repulsion-attraction
like charges repel; unlike charges attract
Inverse Square Law
The force between two charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them
As a charged object gets further away, the influencing charge decreases because of the increased area it affects.
The inverse square law aka:
F= (k q1q2)/ R^2
F- electrostatic force in Newtons
k- constant
q1 and q2- charges in coulombs
R- distance in meters
Coulomb's law
Distribution
Charges reside on the external surfaces of conductors and equally throughout nonconductors
Repel-attraction relationship
Due to this_____
individual electrons repel each other and are distributed at the outer limits of a conductor
Concentration
the greatest concentration of charge will be on the surface with the sharpest curvature
They are subjected to extremely high charges, so concentration on such surfaces could occur and discharge at the wrong moment or in the wrong direction
X ray tubes cannot have sharp or rough edges because:
Movement
only negative charges move along solid conductors (electrons exist outside the nucleus and are not bound, which lets them move easily)
Friction, contact, and induction
Three methods of electrification:
Friction
one object rubs against another and the difference in the number of available electrons causes them to travel between the two; changing the object charges
Contact
simple equalization of charges of touching objects or those in close proximity
Induction
the process of electrical fields acting on one another without contact
electric current
electrons that are moving in predominantly the same direction
vacuum
a space from which air has been removed
Admittance
the measure of resistance in an ac current when the expression 1/R is used
alternating current (AC)
Electrons move first in one direction and then reverse and move in the opposite direction
amp (A)
The unit of current; also known as the ampere
ampere(A)
The unit of current; also known as the amp
=1 Coulomb/1 sec
atomic reactor
a device that converts nuclear energy to electrical energy
battery
a device that converts chemical energy into electrical energy
circuit breaker
A device constructed to interrupt a circuit before a dangerous temperature is reached
concentration
Law of electrostatics that states the greatest intensity of charge will be on the surface where the curvature is the sharpest
conductance
The measure of resistance in a DC current when the expression 1/R is used
conduction band
An area within the force field of an atom beyond the valence band.
conductor
A material that allows electrons to flow freely.
contact
Electrification by contact occurs two objects touch, permitting electrons move from one to another
current
The quantity or number of electrons flowing
direct current (DC)
All electrons travel in the same direction
distribution
Law of electrostatics that states charges reside on the surfaces of conductors but are evenly distributed throughout nonconductors
electrical circuit
A pathway that permits electrons to move in a complete circle from their from their source, through resisting electrical devices and back to the source
electrical field
A force field; the result of the composite forces of the charges residing within an object
electrification
Describes the process of electron charges being added to or subtracted from an object
electromotive force (emf)
The force of the strength of electron flow; also known as potential difference.
electrostatistics
The study of distribution of fixed charges, or electrons, that are at rest
friction
Electrification that occurs when one object is rubbed against another and, due to differences in the number of electrons available on each, electrons travel form one to the other
fuse
a device constructed to interrupt a circuit before a dangerous temperature is reached.
gasses
a light mixture that has neither shape nor volume
generator
a device that converts mechanical energy to electrical energy using moving lines of flux in relationship to a conductor to induce current; also known as dynamo
induction
The process of electrical fields acting on another without contact
insulator
a material that inhibits electron flow
Inverse square law
Law of electrostatics that states the force between two charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.
ionic solution
Charged particles dissolved within a solution
laws of electrostatics
Rules relating how objects are electrified
metallic conductor
The most common pathway for the movement of electrical current
milliamperage (mA)
a measurement of x-ray tube from cathode to anode per second
movement
Second law of electrostatics that states only negative charges move along solid conductors
negative charge
Charge of the electron, which is located outside the nucleus, bound by relatively weak forces.
ohm
The unit of resistance
V=IR
V- potential difference in volts
I- current in amperes
R- resistance in ohms
Ohm's Law
parallel circuit
an electric circuit designed to send electrons through various resistance devices by giving each component its own branch
parallel circuits
The disadvantage to_____ is that with added resistances, more amperage can short circuit the system. Wires become too hot; prevent with circuit breaker or fuse
Total Resistance drops
Total Amperage increases
and Total Voltage stays the same
As more resistances are added to a parallel circuit:
positive charge
Charge of the proton, which is locked within the nucleus by very strong forces
potential difference
The force or strength of electron flow; also known as electromotive force (emf).
potentiometer
a variable resistor that permits a variable contact to slide along a series circuit of its position.
power loss formula
Calculation that can provide an understanding of the changes in resistance to heat output.
repulsion- attraction
Law of electrostatics that states like charges repel and unlike charges attract.
resistance
the amount of opposition to the current in the circuit.
resistance directly proportional to length
R x2 if L x2 and short conducts will offer less resistance
What's the relationship between the length of the conductor and resistance
resistance inversley proportional to cross-sectional diameter
If d x2 then R 1/2 greater resistance with small diameter
whats the relationship between the diameter of a conductor and resistance
Resistance Calculations
R= pL/A
R- resistance in ohms
p- resistivity (function of atomic structure and temp)
L- length in meters
A- area in m^2
Calculate Resistance
rheostat
A device constructed to interrupt a circuit before a dangerous temperature is reached
semiconductor
a material that allows electrons to flow freely under certain conditions (conductor) or that inhibits electron flow under certain conditions (insulators).
Series circuit
An electric circuit designed to send electrons through various resistance
Solar converter
a device that converts solar photons to electrical energy
static discharge
The result of electrons jumping the gap between two objects, one negatively charged and one positively charged, resulting in the equalization of the charges of the two objects.
superconductor
a material that allows electrons to flow freely
vaccuum
a space from which air has been removed
valence energy band
the outermost(sometimes the next-to-outermost) orbital shell.
volt(V)(voltage)
1 volt= 1 joule (J) of work done on 1 coulomb of charge
The unit of potential difference
zero or ground potential
a neutral reference point for discussing charges. The earth is defined as zero; also known as ground potential.
Sets found in the same folder
procedures skull
34 terms
Cranium Evaluation Criteria
26 terms
Procedures (Skull)
61 terms
Ch 33 AEC
15 terms
Sets with similar terms
Principles of radiographic imaging ch. 3
50 terms
RAD131 chapter4
48 terms
Chapter 3: Electricity
38 terms
physics chapter 3 (cody's practice test)
57 terms
Other sets by this creator
Chapter 3
39 terms
Pathology chap4
50 terms
Pathology chap3
70 terms
Pathology chap6
50 terms