Module 4- Electricity

The study of fixed or stationary electric charge

Electrostatics

What an object is said to be if it has too few or too many electrons

Electrified

The removal of electrons by rubbing one object another

This is the simplest method of electrification

This will leave you with objects that have opposite charges

Friction

This type of electrification that occurs when a charged object (that has become charged by friction) touches an uncharged object

Example: Touching a metal doorknob after rubbing your feet on carpet

Contact

Method of electrification that occurs when an uncharged object is brought close to (but does not touch) a charged object, and electrons will transfer to the uncharged object

Example: Lightning

THERE IS NO CONTACT

Induction

The ability to do work when stored energy is released

Electric Potential

The force of attraction between opposite charged or the repulsion between like charges

Electrostatic Force

The electrostatic force is directly proportional to the electric charge and inversely proportional to the square of the distance between the charges

Basically, the stronger the charge, the greater the attraction and the closer the charge the stronger the attraction

Coulombs Law

The study of electric charges in motion

Electrodynamics

Electric charges in motion, or the flow of electrons

Electric Current

An electric current that reverses its direction many times a second

This type of current is often used in power supplies

The type of current we have going to our control panels of our x-ray unit

Alternating Current (AC)

Electric current that only flows in one direction

This type of current is often used in electric vehicles, cell phones, and is the type of current needed in the x-ray tube

Direct Current (DC)

Ability to do work by moving electrons from one point to another

Potential Difference

The flow of electrons

Current

The property that inhibits the flow of electrons

Resistance

A device that measures potential difference

Voltmeter

A device that measures electric current

Ammeter

Converts mechanical energy into electrical energy

Generator

The voltage across the total circuit or any portion of the circuit is equal to the current times resistance

Ohm’s Law

The rate at which electrical energy is transferred by an electric circuit

Electric Power

1 Coulomb=

6.3 × 10^18 electron charges

What is considered to be an electric ground

The earth

What are the factors of an Electric Current

Potential Difference

Current

Resistance

What are the sources of Electric Current or Electric Energy

Battery

Generator

Solar

Nuclear/Atomic Energy

What is the unit of measure for Electric Charge

Coulomb (C)

What is the unit of measure for Electric Potential

Volt (V)

What is the unit of measure for Potential Difference

Voltage (V)

What is the unit of measure for Current or Electric Current

Amperes (A or I)

What is the unit of measure for Resistance

Ohms (Ω)

What is the unit of measure for Electric Power

Watt (W)

What is the unit of measure for Power Loss

Watt (W)

What does this symbol represent?

Voltmeter

What does this symbol represent?

Ammeter

What does this symbol represent?

Battery

What does this symbol represent?

Capacitor

What does this symbol represent?

Resistor

What does this symbol represent?

Transformer

What does this symbol represent?

Diode

What is the Greek letter that acts as the unit of measure for resistance

Ohm Ω

What are the 2 letters that represent the Ampere

A or I

What is the letter that represents resistance

R

What does this picture represent?

Alternating Current (AC)

What does this picture represent?

Direct Current (DC)

What does this picture represent?

Series Circuit

What does this picture represent?

Parallel Circuit

For Ohm’s Law, what is the equation if looking for Voltage

V = I x R

For Ohm’s Law, what is the equation if looking for Amperage

I = V/R

For Ohm’s Law, what is the equation if looking for Resistance

R = V/I

What is the equation for Electric Power

P = V x I

What is the equation for Power Loss

Power Loss = I²R

What is the purpose of the

Converts chemical energy into electrical energy

Provides Electric Potential

What is the purpose of the Capacitor

Stores an electric charge

What is the purpose of the Diode

Allows electrons to flow in only one direction

What is the purpose of the Generator

Converts mechanical energy into electrical energy

What is the purpose of the Transformer

Increases and Decreases Voltage and Amperage with AC

What is the purpose of the Resistor

Inhibits the flow of electrons

What are the 3 methods of electrification

Friction

Contact

Induction

Which method of electrification is the simplest method

Friction

Which method of electrification has no contact at all

Induction

What are the four laws of electrostatics

1) The law of electrostatic force- opposite charges attract, like charges repel

2) Coulombs Law- the stronger the charge, the greater the attraction and the closer the charge the stronger the attraction

3) The surface of a conductor has more electrostatic charges

4) There are more electrostatic charges on the sharpest curve of the surface

Electrostatics AKA

Static Electricity

Electric Potential AKA

Voltage

Electric Current AKA

Electricity

Potential Difference AKA

Electromotive Force

Generator AKA

Dynamo

What are the 4 states of matter

Superconductor

Conductor

Semiconductor

Insulator

What is an example of a superconductor

Titanium

What is an example of a conductor

Copper

Aluminum

What is an example of a semiconductor

Silcon

What is an example of a insulator

Rubber

Glass

Plastic

Wood

Styrofoam

What is the characteristic of a superconductor

Allows electrons to flow with almost NO resistance

Must be very cold

What is the characteristic of a conductor

Electrons can flow easily

What is the characteristic of a semiconductor

Sometimes behave like a conductor, and will sometimes behave like an insulator

What is the characteristic of a insulator

Does not allow electrons to flow easily

Inhibits the flow of electrons

What are the 4 factors that affect resistance

Material

Length of Material

Cross-Sectional Diameter

Temperature

How does the factor “material” affect resistance

Is it a conductor or an insulator

Copper is a conductor and has less resistance

Rubber is an insulator and has more resistance

How does the factor “length of material” affect resistance

The longer the material is, the more resistance there will be

How does the factor “cross sectional diameter” affect resistance

The wider the diameter the less resistance there will be

How does the factor “temperature” affect resistance

The higher the temperature, the more resistance there will be

The colder the temperature, the less resistance there will be

At room temperature all materials will resist the flow of electricity