Radio Waves

​Radio Waves

MELC

​Describe how Hertz produced radio pulses ( S11/12PS-IVi-86)

Objectives:

1. describe how Hertz produced radio pulses or radio waves;

2. perform Science investigation: Wave Blockers; and

3. give the uses of radio waves in communications industry

​What is happening to the radio signals in this picture?

1. The force of attraction or repulsion between electric charges is inversely proportional to the square of the distance between them.

2. Magnetic poles come in pairs that attract and repel each other, much as electric charges do.

​Four main Interactions of electromagnetic forces

3. An electric current in a wire produces a magnetic field whose direction depends on the direction of the current.

4. A moving electric field produces a magnetic field and vice versa

​Four main Interactions of electromagnetic forces

​Electromagnetic Spectrum

What is Radio Waves?

Heinrich Hertz

​

​Conceptual design of Hertz spark-gap transitter

Match

Match the following

• Capacitor

• Electrical transmitter

• Spark gap

• Voltage

• Magnetic induction

a device that is used to store energy

an electronic device which produces radio waves with an antenna

is a space between electrical terminals across which a transient discharge pass.

an electromotive force or potential difference expressed in volts

is the production of of an electromotive force across an electrical conductor

• a device that is used to store energy

• an electronic device which produces radio waves with an antenna

• is a space between electrical terminals across which a transient discharge pass.

• an electromotive force or potential difference expressed in volts

• is the production of of an electromotive force across an electrical conductor

Reorder

Reorder the following

• Hertz put vup his spark-gap transmitter

• Hertz put two hollow spheres of 30 cm diameter with 3m apart.

• A high voltage alternating current electricity was applied across the central spark -gap

• The spark gap produced electrical sparks through a process called magnetic induction

• The sparks flew between sark gaps

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Open Ended

Why do you think Nick's text message was not delivered?

Open Ended

What other factors may have caused delays in delivering text messages?

Open Ended

What do you think is the role of telecommunications company in the delivery of information?

Open Ended

Radio waves are widely used in communications industry. Aside from mobile phones that use radio waves to carry signals, list down at least five other uses of radio waves to communicate and deliver information.

​Thoughts to ponder