2-3 Electromagnetic radiation

• Natuurkunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Electromagnetic 

radiation (p. 62)

What you need:

- Textbook, writingbook, iPad

- Pen, pencil, geotriangle

- Calculator

Schoolbags in the cuboard

Phones in the phonebag

Bluetooth 

- ON

- VPN off

    Lesson today:

- Lesson goals (5 min)

- Phet simulation (5 min)

- Lesson content (15 min)

- Work by yourself (10 min)

- Corrections (5 min)

- Conclusion (5 min)

                       Lesson goals:

       - Phet simulation: Generating a current

        - Explain what determines the colour of 

           a lamp. 

  - Explain how EM- radiation works

- Explain how a GPS and GSM work. 

- Explain how a microwave oven works.

https:

What determines the colour of a lamp?

Filament light bulb: temperature of the filament

Fluorescent tubing: powder coating

Neon/ sodium lamp: The gas

LED lamp: material/ semi-conductor

How does EM radiation work

• Telephone - mobile phone sends a signal to a phone mast (10km).
• Radiation has something to do with magnetism.
• Electromagnetic radiation is produced when an electric current passes back and forth along a wire (quickly).
• This is called an electromagnetig vibration or oscillation. 
• The arial of your phone works in this manner.

gsm en gps

gsm: Global system for 

            mobile communications

gps: Global positioning system

• Your phone continuously sends a signal to the nearest mast. 
• GPS receives a signal from a satalite. This is also an electromagnetic signal. 

Microwave oven:

• Also has an arial that emits electromagnetic radiation. 
• This heats up the water and fat particles in food. 
• This way, it heats up from the inside.

Grill - also makes use of radiation 

hereby a crispy crust is created. 

Combination oven - 

microwave oven and grill

What determines the colour of the light in a fluorescent tube?

1. gas
2. powder/ coating in the tube
3. material
4. temperature

What determines the colour of a neon lamp?

1. gas
2. powder
3. material
4. temperature

Inside an arial there is a magnet.

1. true
2. false

An arial moves an electric current to and fro.

1. true
2. false

Radiation is reflected back by a second arial.

1. true
2. false

Which apparatus makes use of an antenna

1. microwave oven
2. grill
3. oven
4. baking plate

Now do  15 up to 17 (p. 63)

WHEN YOU ARE DONE: write a paragraph on how a microwave oven works

RULES:

• Write in your writingbook
  



• Use: Your textbook
• No discussion
  


• In 8 minutes we will discuss the answers
  

Conclusion