Electrostatics, Electricity and Magnetism

What is the electromagnetic energy Srectum? 

This is the continuous range of energy, spectrum indicates that the distribution of energies exists in an uninterrupted band, it moves through space or matter as oscillating magnetic electric fields. 

What is the speed of light?

This is represented by '“c” which is constant

c=3X10^8m/s

what is wave count 

Frequency f or v

number of cycles per unit times (s) 

Unit of measure is hertz (Hz)

How does energy affect wavelength?

As the energy increases wavelength decreases,

As energy decreases wavelength increases

this is an inversely proportional relation  

What is the relationship between energy and wavelength?

As the energy increases the wavelength decreases as energy decreases wavelength increases.

What is attenuation?

This is the reduction in the number of x-ray photons.

What is refraction?

Deviation in the line of travel of a light photon, x-ray cannot be refracted but scattered. ex like a spoon in a water cup

What is radiolucent?

this is x-ray easily penetrate like air ex. the lungs

What is radiopaque?

X-ray are absorbed like bone and metal.

What are Beta particles and gamma rays?

Beta particles, like electrons except originate in nucleus of radioactive isotopes

Gamma rays, Like x-rays except originate in nucleus of radioactive isotopes.

What is inverse square law? 

Unit of mesure is R or mR 

x-rays in air are measured in Roentgen 

Radiation over area; Radiation intensity 

Radiation intensity is inversely proportional to the square of the distance 

I/i=d²/D²

What is electrostatics?

This is the study of electric charges in stationary form

What is electrification?

Is too few or too many electrons

What are the methods of electrification?

Friction, Contact( conduction), induction

What is friction?

The transfer of electrons by rubbing objects together

What is contact?

Also known as conduction, this is the transfer of electrons by touching an electrified object to another object.

What is electroscope?

Electroscope that measures the amount of static electricity

What is induction?

the charged and uncharged objects do not touch.

What is the law of electrostatics?

This is when like charges repel and unlike attract.

What is coulomb’s Law?

also known as the electrostatic law, the force between tow charges is directly proportional to the magnitude of the two charges and inversely proportional to the square of the distance between the objects

Distribution of charge 

Over outer surface only of a dense conductor or a hollow object. 

Concertation of charge where is it more likely to pool?

Concentrated at the sharpest curves on irregular objects

What is the lines of force vs strength of field?

Strong fields= more lines of force also equal closer lines of force

Electrodynamics what is it?

This is the study of electric charges in motion

circuit is a closed loop that conducts electricity a path along which electrons can move.

conductor? 

It allows electrons to flow things like metal and water is a conductor. 

insulator?

A non conductor or dielectric which inhibits the flow of electrons things like rubber are insulator.

Semiconductor?

This acts as both a conductor and an insulator like silicon.

Superconductor?

This Allows electrons to flow without resistance elements like niobium and titanium are superconductor.

What are the components of a circuit?

Current amperage= I , I is for intensity the French word Andre-Mare Ampere to describe the intensity of current

Potential Difference= voltage (V)

Resistance = ohms (R)

What is the unit of current?

Ampere (charge/time)

Amp= A or mA=.001

What is Potential Difference?

Electromotive Force, EMF= Voltage 

the force that causes charges to move 

electrical push or pull

results in a current flow in a circuit 

Work =energy that moves charges from one point to another

If pottentials are connected by a conducting path electrons path electrons will flow from high to low (negative to positive)

What is resistance?

Anything that opposes or limits a current

measures in ohms

reparented by R

What happens when the material conductor low R vs insulator high R?

Length of path increases R with increased in length

Cross sectional area increased R with decreased in cross section

temperature increased R with increased in temperature

super conductors lose all R at extremely low temperatures

Meters 

Devices to determine electrical values in a circuit 

Voltmeter?

Voltmeter measures potential difference this is connected across load parallel connection meaured in Volt V

Ammeter

This measures current, it is connected in path so all electrons pass thrugh it series connection

mesured in Amperes A

ohms law ? 

Voltage in a circuit will be equal to the current times the resistance 

V=IXR

Electric Power

The amount of work that a circuit can do, Rate of change in electrical energy

P=VXI

unit is watt W =j/s

what is the formula for power using I and R?

P=I² R

Direct current 

This is when electrons flow in one direction though the circuit path there is two types there is a steady direct current and a pulsed current

Alternation current

electron flow one way then the opposite way

capacitor

Device that temporarily stores charge in an electric circuit 

this is the metal plate that stores the charge

capacitance?

Ratio of charge stored to potential difference between plates

What is magnetism?

Charged particles in motion exhibit magnetism 

Magnetic Domain is accumulation of many atomic magnets

 SI units for Magnetism

this is Telsa (T) and Gauss (G)

G=1X10^-4 T

G=0.0004 T

classification of magnets

there is natural, artificial permanent, electromagnets

Natural magnets

are found in nature earth is a dipole magnetite (iodestone or iron oxide) natural ore that exhibits magnetism

Artificial permanent

Man made magent hardened steel or alloy like alnico like a compass

Electromagnets

Temporary magnet created by a current of electron and iron core

Magnetic Permeability 

Susceptibility, ease with which material can be magnetized 

Magnetic retentivity

Ability of a material to hold magnetization

What is the relationship between permeability and renetivity?

they are inversely related

Ferromagnetic

Materials that can be magnetized, exhibits strong magnetic properties, are strongly attracted to a magnet

Paramagnetic 

Materials that are only weakly attracted to a magnetic field loosely influenced by a magnetic field

Diamagnetic

Are weakly repelled by a magnetic field these materials cannot be magnetized and are not attracted to a magnet

most elements in the periodic table including coper silver and gold are diamagnetic

Nonmagnetic

Materials unaffected by a magnetic field

Laws of magnetism

Every magnet has two poles designated N and S

Like poles repel unlike poles attract

Analogous to coulombs law, the force between two magnetic poles caries directly as the strength of the poles and inversely as the square of the distance between poles