* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download electricity : answer key
Rectiverter wikipedia , lookup
Music technology wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Charge-coupled device wikipedia , lookup
Valve RF amplifier wikipedia , lookup
Night vision device wikipedia , lookup
Radio transmitter design wikipedia , lookup
Integrated circuit wikipedia , lookup
Music technology (electronic and digital) wikipedia , lookup
Regenerative circuit wikipedia , lookup
Oscilloscope types wikipedia , lookup
Home cinema wikipedia , lookup
Index of electronics articles wikipedia , lookup
Cavity magnetron wikipedia , lookup
Public address system wikipedia , lookup
Oscilloscope history wikipedia , lookup
Beam-index tube wikipedia , lookup
Video camera tube wikipedia , lookup
ELECTRICITY : ANSWER KEY SECTION REVIEW 4-1 1. ELECTRONICS STUDIES THE RELEASE, BEHAVIOR, AND EFFECTS OF ELECTRONS USED TO CARRY INFORMATION. ELECTRICITY USES ELECTRIC CURRENTS TO POWER DEVICES BY CONVERTING THE ENERGY OF MOVING ELECTRONS INTO HEAT AND LIGHT ENERGY. 2. ELECTRONS IN A VACUUM TUBE FORM A CURRENT; A VACUUM TUBE IS USED AS A RECTIFIER TO CHANGE ALTERNATING CURRENT (AC) INTO DIRECT CURRENT (DC); VACUUM TUBES ARE USED IN AMPLIFIERS TO INCREASE THE STRENGTH OF AN ELECTRIC SIGNAL. 3. SEMICONDUCTORS ARE DEVICES THAT CAN CONDUCT ELECTRICITY BETTER THAN INSULATORS CAN, BUT NOT AS WELL AS METALS CAN. 4. AN INTEGRATED CIRCUIT COMBINES MANY DIODES AND TRANSISTORS ON A THIN SLICE OF SILICON CRYSTAL, AND A SINGLE ITEGRATED CIRCUIT MAY OFTEN CONTAIN THOUSANDS OF DIODES AND TRANSISTORS IN A VARIETY OF COMPLEX COMBINATIONS. AN ADVANTAGE OF INTEGRATED CIRCUITS IS THAT THEY ARE MUCH SMALLER AND HAVE GREATER PERFORMACE THAN VACUUM TUBES. SECTION REVIEW 4-2 1. IN DEVICES THAT TRANSMIT SOUND, SOUND VIBRATIONS ARE CHANGED INTO ELECTROMAGNETIC WAVES, WHICH ARE THEN CONVERTED BACK INTO SOUND VIBRATIONS. 2. TRANSMITTER AND RECEIVER. THE TRANSMITTER DETECTS VIBRATIONS, CHANGING THEM INTO ELECTRIC CURRENT; THE RECEIVER CHANGES THE ELECTRIC CURRENT BACK INTO SOUND VIBRATIONS. 3. ANSWERS MAY VARY SLIGHTLY. STUDENTS MIGHT SUGGEST THESE STEPS: SOUND WAVES, MICROPHONE, AUDIO SIGNAL, TRANSMITTER, TRANSMITTING ANTENNA, RADIO WAVES, AUDIO RECEIVING ANTENNA, RECEIVER, AMPLIFIER, AND SOUND. 4. ACCEPT LOGICAL RESPONSES. STUDENTS MIGHT SUGGEST THAT TELEPHONES AND RADIOS HAVE BECOME SMALLER IN SIZE AND MORE PORTABLE. SECTION REVIEW 4-3 1. IT IS AN ELECTRONIC DEVICE THAT USES ELECTRONS TO PROCUCE IMAGES ON A SCREEN. AN ELECTRIC CURRENT HEATS A METAL FILAMENT IN THE CRT, WHICH THEN EMITS ELECTRONS. THE ELECTRONS ARE ACCELERATED THROUGH A MAGNETIC FIELD, WHICH FOCUSES THE ELECTRONS INTO A BEAM. ELECTROMAGNETS PLACED OUTSIDE THE CRT CAUSE THE BEAM OF ELECTRONS TO CHANGE DIRECTION. AT EACH POINT WHERE THE ELECTRONS STRIKE THE FLUORESCENT MATERIAL OF THE CRT SCREEN, VISIBLE LIGHT IS GIVEN OFF. 2. IN A COLOR CRT, THE SCREEN IS COATED WITH 3 DIFFERENT MATERIALS THAT CAN GLOW WITH RED, BLUE, OR GREEN LIGHT. A SIMPLE CRT HAS A COATING OF ONE MATERIAL. A COLOR CRT ALSO DIFFERS FROM A SIMPLE CRT IN THAT IT HAS 3 ELECTRON “GUNS” RATHER THAN JUST ONE. SECTION REVIEW 4-4 1. AN ELECTRONIC DEVICE THAT PERFORMS CALCULATIONS AND PROCESSES INFORMATION. THE HARDWARE OF A COMPUTER EXECUTES INSTRUCTIONS AND COMMANDS, AND THE SOFTWARE PROVIDES THE INSTRUCTIONS, OR THE STEPS, FOR THE COMPUTER TO FOLLOW. 2. A MODEM IS BOTH AN INPUT AND AN OUTPUT DEVICE. IT CAN INPUT OR OUTPUT INFORMATION USING PHONE LINES AND CAN CONNECT WITH HUGE BANKS ON INFORMATION (DATA BANKS) FOR USE BY THE COMPUTER OPERATOR. 3. THE BINARY SYSTEM IS A MATHEMATICAL SYSTEM USING ONLY 2 NIMBERS, 0 AND 1. BECAUSE THE SWITCHES IN A COMPUTER CAN BE IN ONE OF 2 POSITIONS, EITHER ON OR OFF, THE BINARY NUMBERS REFERS TO A SWITCHING POSITION.