2 EM Waves

Question 1

A disturbance that transfer energy from one place to another

Answer 1

Wave

Question 2

TWO IMPORTANT WAYS ON HOW
ENERGY IS TRANSPORTED

Answer 2

1. MECHANICAL WAVES
2. ELECTROMAGNETIC WAVES

Question 3

is a wave that is not capable of transmitting its
energy through a vacuum.
- It requires medium to propagate

Answer 3

MECHANICAL WAVES

Question 4

• It does not require a medium to propagate.
• Can travel not only through air and solid materials,
  but also through vacuum

Answer 4

ELECTROMAGNETIC WAVES

Question 5

How are EM waves formed?

Answer 5

Electromagnetic waves are formed when an electric field comes in contact with
magnetic field.

Question 6

Electric field and magnetic field of an
electromagnetic waves are __________to each other

Answer 6

perpendicular

Question 7

Electromagnetic waves are considered as __________waves.

Answer 7

transverse

Question 8

Electromagnetic waves travels with a constant velocity of ____________ in vacuum

Answer 8

3.00X10^8 m/s

Question 9

height of a wave, usually measuredin meters (m).

Answer 9

Amplitude

Question 10

• the distance between two
  consecutive crests or troughs of a wave.

Answer 10

Wavelength (ƛ)

Question 11

name of the symbol for wavelength

Answer 11

lambda (λ / ƛ)

Question 12

• the number of waves passing a
  point in a certain time. Usually measured in (1/s)
  or Hz.

Answer 12

Frequency (f)

Question 13

c =
ƛ =
f =

Answer 13

speed of light in vacuum
wavelength
frequency

Question 14

triangle formula

Answer 14

C
ƛ f

Question 15

Types of Electromagnetic Waves:

Answer 15

● Radio waves
● Microwaves
◾visible light
● Infrared
● Ultraviolet
● X-ray
● Gamma Ray

Question 16

As you move from left to right of the
Electromagnetic Spectrum, the
wavelengths get __________and
frequencies get ___________.

Answer 16

(λ)–> smaller
(f)–>higher

Question 17

The ____________ contains region of
electromagnetic waves from longest wavelengths to shortest wavelengths and from lowest frequencies to highest frequencies.

Answer 17

electromagnetic spectrum

Question 18

Frequency is measured in ________ or _______

Answer 18

cycles per second or Hertz

Question 18

Wavelength is measured in ________

Answer 18

meters

Question 19

The frequency of an EM wave is ______________ to
energy.

Answer 19

directly proportional

Question 20

In 1803, ___________ provided the first experimental evidence for a wave theory of light.

Answer 20

Thomas Young

Question 21

By the 1860s and 1870s , ____________ had provided a convincing wave description of light and other forms of electromagnetic radiation.

Answer 21

James Clark Maxwell

Question 22

• Verified the predictions of
  Maxwell. EM waves are
  sometimes called Hertzian
  waves.
• He showed how
  electromagnetic waves can
  be generated and detected

Answer 22

Heinrich R. Hertz(1888)

Question 23

EM waves that are invisible to the human eye.
Longest wavelength, lowest frequency

Answer 23

Radio waves

Question 24

Production of Radio waves:

Answer 24

Making electricity oscillate in an antenna

Question 25

Frequency range of Radio waves

Answer 25

30Hz - 300GHz

Question 26

Used in satellite communications, radar, phone networks, for cooking Radio waves of very short wavelength Generated by electronic devices

Answer 26

Microwaves

Question 27

Waves produced by hot objects Lie in the region beyond the red end spectrum. Most noticable when given off by hot objects, especially when objects are red hot. Also called thermal or heat radiation

Answer 27

Infrared Waves

Question 28

Uses of Infrared Radiation: (5)

Answer 28

Pictures from satellites Infrared scanners Remote controllers Infrared telescopes Autofocus cameras

Question 29

Can be detected by the human eye Caused by motion of electrons in an atom as they jump between orbits

Answer 29

Visible waves/ Visible light

Question 30

Produced by motion of electrons in atoms Can cause chemical change in skin pigments resulting in skin darkening Can cause damage in skin cells, cause sunburn and skin cancer.

Answer 30

Ultraviolet Waves

Question 31

Invisible radiation that lie beyond the violet end of the visible spectrum

Answer 31

UV waves

Question 32

3 types of UV waves

Answer 32

UV-C UV-B UV-A

Question 33

Describe UVC, UVB, UVA

Answer 33

UV-C = shortwave, disinfection UV-B = small, most dangerous UV-A = long wave, skin aging

Question 34

Uses of UV radiation: (4)

Answer 34

Production of vitamin D Sterilizing water UV lamps to check bank notes Paints with fluorescents

Question 35

Have short wavelengths and high frequencies and are very penetrating. Can damage living cells and cause cancer Produced by rapid acceleration of electrons

Answer 35

X-rays

Question 36

Uses of X-ray (5)

Answer 36

X-ray photography to inspect welded joints of faults Crystallography Astrophysics Remote sensing

Question 37

Has highest energy in the em spectrum Produced from nuclear reactions High doses can kill

Answer 37

Gamma Rays

Question 38

Uses of Gamma Rays (5)

Answer 38

Kills cancer cells Sterilizing medical equipment Nuclear research Geophysics Mineral exploration

Question 39

Each particle contains a bundle of energy called a

Answer 39

Photon

Question 40

He discovered the existence of infrared by passing sunlight through a prism

Answer 40

Sir William Herschel

Question 41

The process of emitting energy

Answer 41

Radiation