Chapter 4

Text pages 88 - 119

Electric Current Flow

• A greater force will make a larger current flow• If a larger wire is used, there is less resistance & more current will flow • The equation that describes current flow in an electrical circuit is called

Ohm’s Law• If voltage (force) gets larger, current gets larger• If Resistance gets larger, current gets smaller

• Current (amps) = Voltage (volts) / Resistance (ohms)

• I = V/R

The flow of electrical current through a wire is similar in concept to the flow of water though a pipe…

Computer Systems

• PROCESSOR – Heart of the computer

• MEMORY - Place the program is stored

• INPUT - Information given to a computer

• OUTPUT - Screen display or hard copy

Computer Input Devices

• Keyboard & Tapes

• Light/Touch Sensitive Screens

• Hard & Floppy Discs

• Optical Character Reader

• Speech Recognition

• Mouse & Light Pens

Computer Output Devices

• Video Monitor(Cathode Ray Tube Screen)

• Printers -- Hard Copy(Dot Matrix, Laser, Ink Jet)

• Audio Output(Tones, beeps, music, voice)

Types of Computers

• Micro-Computers(cars, appliances & computers)

• Minicomputers(used by small companies & individuals)

• Main-Frame(used by universities, large companies and agencies)

• Supercomputers(used for research)

Software

• Operating System(Allows user to control & access memory, printer & peripheral devices – MSDOS, Windows)

• Applications Program(Tells computer to carry out specific tasks – Games, Word Processing, Car Engine Control Programs)

• Programming Languages(Pascal, Basic)

Ch 4 Assignments

Group 1:• Use these notes and “Living with Technology” text

book to complete the Chapter 4 Work Sheet, Q’s & Terms. – * Do Q’s 3 & 7 on page 115. – Define the following Terms: – Complete Ch4 Worksheets (T/F, Multiple-Choice, Fill-in-Blank)

Group 2:• Complete DC Circuit Quest (See assignment page)• Pass in