Chapter 4 Handout Flashcards
Primary function: to convert electric energy
into electromagnetic energy.
X-ray Imaging System
The study of stationary electric charges
Electrostatics
Matter has mass & energy equivalence. Matter also may have _____!
electric charge
Fundamental Unit (SI) of Electric Charge:
coulomb (C)
1 C = ???
6 x 10^18 electron charges
The object that has too few or too many
electrons
Electrified
- The process of adding or removing electrons from an object.
- It is created by contact, friction or by
induction
Electrification
The object that behaves as a reservoir for
stray electric charges.
Electric Ground
Electric field radiate ___ from positive
charge; Electric field radiate ____ a negative charge
out ; toward
What particles do not have electric
field?
Uncharged Particles
The lines of force exerted on charged ions in the tissues by the electrodes.
Electric Field
Positive charge: points _____
Negative charge: points _____
outward ; toward
- The force of attraction between unlike
charges or repulsion between like charges - Directly proportional to the product of the charges
- Inversely proportional to the square of the distance between them
Electrostatic Force
The electrostatic force is directly proportional to the product of the electrostatic charges & inversely proportional to the square of the distance
between them
Coulomb’s Law
Electric charge distribution is ______
throughout or on the surface!
uniform
Electric charge of a conductor is concentrated along the __________.
the sharpest curvature of the surface!
SI Unit of Electric Potential:
Volt (V)
1 V:
1 J/C
The study of electric charges in motion
Electrodynamics
Work with electric current
Electrical Engineer
Concerned with electron flow
Physicist
Four States of Matter
Conductor, Insulator, Semiconductor,
Superconductor
Any substance through which electrons flow easily
Conductor
Examples: copper (Z=29), aluminum (Z=13)
& water
Any material that does not allow electron
flow
Insulator
Examples: glass, rubber & clay
A material that some conditions behaves as
an insulator & as a conductor
Semiconductor
Any material that allows electrons to flow
without resistance
Superconductor
He demonstrated semiconduction
William Shockley (1946)
The property of some matter to exhibit no
resistance below a critical temperature
Superconductivity (1911)
The path of electron flow from the generating source through the various components & back again
Electric Circuits
Increasing electric resistance results in a
reduced ______!
electric current
The flow of electrons through a conductor
Electric Current/Electricity
It is measured in ohms (Ω)
Electric Resistance
It is measured in volts (V)
Electric Potential
The voltage across the total circuit or any
portion of the circuit is equal to the current
times the resistance
Ohm’s Law
Two Basic Types of Electric Circuits
Series & Parallel Circuits