Electromagnetic Waves

Question 1

Is the time for one wavelength to pass a point.

Answer 1

Period (T)

Question 2

Is the speed at which a specific part of the wave passes a point.

Answer 2

Velocity (V)

Question 3

Two types of Waves

Answer 3

Transverse Waves and Longitudinal Waves

Question 4

• Is a disturbance in a medium that carries energy without a net movement of particles.
• It may take the form of elastic deformation, a variation of pressure, electric or magnetic intensity, electric potential, or temperature.
  Transfers energy.
• Usually involves a periodic, repetitive movement.
• Does not result in a net movement of the medium or particles in the medium (mechanical wave).

Answer 4

Waves

Question 5

Is the distance between two successive identical parts of the wave.

Answer 5

Wavelength

Question 6

Is the maximum displacement from the neutral position.

This represents the energy of the wave.

Greater amplitude carries greater energy.

Answer 6

Amplitude

Question 7

Is the number of repetitions per second in Hz

Answer 7

Frequency (F)

Question 8

Is the position of a particular point in the medium as it moves as the wave passes.

Answer 8

Displacement

Question 9

Waves in which the medium moves at right angles to the direction of the wave.

Answer 9

Transverse Waves

Question 10

High point of a transverse wave

Answer 10

Crest

Question 11

Lowest point of a transverse wave

Answer 11

Trough

Question 12

A wave that has the movement of the particles in the medium in the same dimension as the direction of movement of the wave.

Answer 12

Longitudinal Waves

Question 13

A part of the longitudinal wave where the particles are close together.

Answer 13

Compression

Question 14

A part of the longitudinal wave where the particles are spread apart.

Answer 14

Rarefraction

Question 15

Examples of Longitudinal Waves

Answer 15

• Sound waves
• P-type earthquake waves
• Compression wave

Question 16

Examples of Transverse Waves

Answer 16

• Water waves (ripples of gravity waves, not sound through water)
• Light waves
• String Instrument
• Torsion waves
• S wave earthquake waves

Question 17

• The higher the frequency, the higher the energy carried by the wave.

Answer 17

ELECTROMAGNETIC (EM) WAVES

Question 18

• Cannot penetrate the cells of organisms. ex, microwaves, radio waves, infrared, visible light, UV rays

Answer 18

NON-IONIZING RADIATION

Question 19

can penetrate the cells of organisms. It can cause biological damage.
ex. Xrays, Gamma rays

Answer 19

IONIZING RADIATION

Question 20

⚫ are the region in the EM spectrum with the longest wavelength and lowest frequencies.
* Wavelengths: 1 cm to 1 km
* Frequencies: 30 gigahertz to 300 kilohertz.

Television and FM and AM radio broadcasts, military communications, mobile phones, ham radio, wireless computer networks, and numerous other communications applications.

Answer 20

RADIO WAVES

Question 21

⚫ with frequencies less than 3KHz and wavelengths greater than 100 km.
* also known as myriameter band
⚫ used for military communications with submarines because of the ability to penetrate saltwater up to certain depths.

Wireless transmission of sound messages, or information, for communication, as well as for maritime and aircraft navigation.
* Naturally generated in the atmosphere.

Answer 21

Extremely low frequency waves

Question 22

⚫ with frequency 30 to 300 KHz and wavelengths ranging from 1m to 10 km
⚫ used for long distance
communication.

Answer 22

Low frequency waves

Question 23

⚫ with frequencies ranging from 300 kHz to 3 MHz and wavelengths from 100m to 1 km.
⚫ used for amplitude modulation (AM) broadcasting and air traffic control.

Answer 23

Medium-frequency waves

Question 24

⚫ with frequencies ranging from 3 to 30 MHz and wavelengths ranging from 10 to 100m.
* used for international broadcasting.

Answer 24

High-frequency waves

Question 25

⚫with frequencies ranging from 30 to 300 MHz and wavelengths ranging from 1 to 10m. ⚫ used for digital audio broadcasting and mobile radio systems.

Answer 25

Very high-frequency waves

Question 26

⚫ with frequencies ranging from 300 MHz to 3 GHz and wavelengths ranging from 1cm to Im. ⚫ used for TV broadcasting, GPS, Wi- Fi, Bluetooth.

Answer 26

Ultra high-frequency waves

Question 27

* Frequency: 300 MHz to 300 GHz. * Sub-bands: L,S,C,X, and K. * L-bands used for GPS. * Other bands are used for RADAR systems.

Answer 27

Micro-wave

Question 28

* Frequency: 3 x 10^11 to 4 x 10^14 Hz * Grouped into: Near, mid, and far infrared regions. * Invisible to an unaided eye but can be detected in the form of heat. * In 1800, William Herschel first recorded the thermal measurement at the far end of the red spectrum. * Used in remote sensing. * the remote controls of the TV sets use IR to send signals to change channels. used in thermal imaging.

Answer 28

INFRARED

Question 29

*The part of the EM spectrum that can be seen by the naked eye. * Frequency: 400 to 700mm * Spectral Signatures: patterns of dark lines and colors, used in identifying structure and composition of substances.

Answer 29

VISIBLE LIGHT

Question 30

* In 1801, John Ritter successfully proved the existence of energy beyond violet spectra. * Wavelength: 10 to 400mm

Answer 30

ULTRAVIOLET WAVES

Question 31

UVA

Answer 31

Least Harmful

Question 32

UVB

Answer 32

Can cause sunburn

Question 33

UVC

Answer 33

Most harmful but is absorbed by the ozone layer

Question 34

* First observed by Wilhelm Conrad Roentgen in 1895. * The wavelengths are small, energies carried are described in electron volts (eV) * Soft Xrays carry smaller amounts of energy compared to hard Xrays. * These energy allows them to penetrate through matter.

Answer 34

X - RAYS

Question 35

* found at the end of the EM Spectrum. ⚫ contains the highest energy of all. ⚫ are produced by objects with very high energy.

Answer 35

GAMMA RAYS

Question 36

Wave that need medium to propagate

Answer 36

Mechanical wave

Question 37

Wave that doesnt need medium to propagate

Answer 37

Em waves