Ch 4 Application of Electromagnetic Waves Electromagnetic Spectrum
- Slides: 25
Ch. 4 Application of Electromagnetic Waves
Electromagnetic Spectrum (電磁波譜) lowest frequency highest frequency
Electromagnetic spectrum: 1. Radio Waves (無線電波) 2. Microwaves (微波) 3. Infra-red rays (紅外線) 4. Visible Light (可見光) 5. Ultra-violet rays (紫外線) 6. X-rays (X光) 7. Gamma rays (伽瑪射線) Note: We can see the visible light only. 3
Applications (應用) of Electromagnetic Waves (電磁波 ) 4. 1 Radio Waves (無線電波) (a) Radio (電台) and Television (電視) broadcast (廣播) Radio Waves Antenna (receiving signals) reproduced sound original sound Aerial (transmitting signals) 4
(b) Wireless telecommunication (無線通訊) in mobile phone (手提電話) wireless computer network (無線電腦網絡) Bluetooth (藍芽) headset Walkie talkie (對講機) 5
4. 2 Microwaves (微波) (a) Satellite Communication (衛星通訊) satellite 6
(b) Radar (雷達) microwaves 7
Class Exercise 4. 1 The US F-117 fighters are designed to be invisible to radar. Suggest some of its features (特徵). 8
Class Exercise 4. 1 The US F-117 fighters are designed to be invisible to radar. Suggest some of its features (特徵). 1. Surface layer can absorb microwaves. 2. Large flat areas on the top and bottom of the aircraft reflect most of the incoming microwaves. 9
(c) Microwave Oven (微波爐) 10
4. 3 Infra-red Radiation (紅外輻射) (a) Remote Control (遙控) 11
(b) Infrared Thermometer (溫度計) (c) Thermography (熱力圖) 12
(d) Infrared Camera (紅外線相機) 13
(e) Infrared Sensors (紅外線感應器) 14
(e) Infrared Sensors (紅外線感應器) 15
4. 4 Ultra-violet rays (紫外線) (a) Checking of banknotes (核對鈔票) 16
(b) Sterilisation (消毒) 17
(c) Making of vitamin D (維生素D) 18
Class Exercise 4. 2 Suggest some methods to prevent over exposure (暴露) to UV radiations? 19
Class Exercise 4. 2 Suggest some methods to prevent over exposure (暴露) to UV radiations? 1. 2. 3. 4. 5. 6. Use Suntan lotion (防曬油) Wear Hat Wear Anti-UV cloth Wear Sunglasses Use Umbrella … 20
4. 5 X-rays (X光) (a) medical diagnosis (醫學診斷) 21
4. 5 X-rays (X光) (b) inspect luggage (檢查行李) 22
4. 6 Gamma rays (伽瑪射線) (a) Radiotherapy (放射治療): killing cancer cells (殺癌細胞) 23
(b) Sterilisation (消毒) of medical equipment. 24
Homework: Assignment Book 1. Chapter 3 Q. 1 – Q. 3 (p. 4) Chapter 4 Q. 1 – Q. 4 (p. 5 -6) 2. Deadline: 6 -10 -2010 (Wed) 25
- Electro magnetic scale
- Mechanical and electromagnetic waves similarities
- Transfer of energy when a wave disappears into a surface
- Mechanical wave and electromagnetic wave
- Difference between mechanical and electromagnetic waves
- Mechanical waves and electromagnetic waves similarities
- Electromagnetic waves are transverse waves true or false
- Examples of mechanical and electromagnetic waves
- Mechanical waves and electromagnetic waves
- Copper subshell configuration
- Absorption spectrum vs emission spectrum
- Ultraviolet wave characteristics
- Electromagnetic spectrum foldable
- Electromagnetic spectrum foldable
- Lesson 1 the electromagnetic spectrum
- Maxwell theory of light
- Longest wavelength to shortest
- Electromagnetic waves table
- Types of radiation in the electromagnetic spectrum
- Electromagnetic spectrum micrometers
- Darvill clara electromagnetic spectrum
- Retinine
- Light has a dual nature
- Chapter 18 electromagnetic spectrum and light
- Electromagnetic star
- Electromagnetic spectrum