Physics Chapter 13 - (Electromagnetic Spectrum)

Define the term “Electromagnetic Spectrum”.

Electromagnetic waves that travel from light.

Electromagnetic Spectrum from lowest energy, wavelength and frequency to the highest energy, wavelength and frequency.

Radio waves → Microwaves → Infrared → Invisible light → Ultraviolet → X-Rays → Gamma Rays.

How fast do all electromagnetic waves travel in a vacuum?

3 × 10⁸m/s.

Formula for calculating electromagnetic wave speed.

V = fλ.

Define the term “Electromagnetic Radiation”.

The energy that is being transferred by electromagnetic waves.

What are radio waves and what do they do?

Have the lowest frequencies and energy.

Used in radio and television transmission.

Used for RFID purposes.

What is microwave radiation and what does it do?

Causes water molecules to vibrate and heat up quickly.

Used for communication from geostationary satellites or phones.

What is infrared radiation and what does it do?

Causes heating and generates heats from invisible waves.

Used in an electric grill by transferring infrared radiation to cook the food.

Used in thermal imaging.

What is visible light radiation and what does it do?

Can be seen by human vision.

Used for photography or fiber optics.

What is ultraviolet radiation and what does it do?

Violet-blue end of the visible spectrum.

Damages cells and microorganisms.

Used for security checking (fake bank notes).

What are X-Rays and what do they do?

Radiation that penetrates soft tissues but blocked by bones and tumors.

Used for medical scanning and security scanners (e.g locating hidden weapons or contraband).

What are Gamma rays and what do they do?

Produced by radioactive nuclei decay.

Used for sterilizing medical equipment or killing cancer cells (e.g radiotherapy).

What are fiber optic cables and what are they used for?

Transmit energy more far and faster than a copper wire without losing energy.

Typically used for television cables and high speed internet access.

Differences between a digital and an analogue signal.

Digital signal: Has fixed values 1 and 0 that indicate on and off.

Analogue signal: Continuous values in time.

Benefits of digital signals.

More data can be transmitted with higher quality.

Signals have less noise.