chapter 13

Question 1

which is the lowest frequency on the em spectrum

Answer 1

radio waves

Question 2

which is the higest frequency on the em spectrum

Answer 2

gamma

Question 3

what colours of the spectrum does white light contain

Answer 3

all of them

Question 4

what colour has the shortest wavelength

Answer 4

violet

Question 5

what colour has the longest wavelength

Answer 5

red

Question 6

name 3 uses of light

Answer 6

torches cameras and optical fibres

Question 7

do all objects give off infrafred radiation even if they are below freezing

Answer 7

yes

Question 8

name 3 uses of infrared radiation

Answer 8

optical fibres remote controls and ovans

Question 9

name 3 uses of microwaves

Answer 9

mobile phones microwave oven and sateliite oven

Question 10

what is the wave length of a radio wave

Answer 10

range from milli meteres to kilometers

Question 11

name 3 uses of radio waves

Answer 11

radio bluetooth and remote control car

Question 12

what dangers can infrared pose

Answer 12

skin burns

Question 13

what dangers can microwaves and radio waves pose

Answer 13

heating internal body parts

Question 14

what waves can damage eye sight

Answer 14

visible light and infrared

Question 15

what type of waves fit into the electromagect spectrum

Answer 15

transverse

Question 16

what are waves in the electromagnectic spectrum

Answer 16

electric and magnetic disturbances thatn that transfer energy (not matter)

Question 17

as you move from left to right across the electromagnetic spectrum what happens to the waves

Answer 17

the wavelength gets smaller and the frequency gets bigger

Question 18

what wavelengths can the human eye see

Answer 18

350nm-650nm

Question 19

what speed to all electromagnetic waves travel at in a vacuum

Answer 19

3x10 8 m/s

Question 20

what is the equation for wave speed

Answer 20

wavepeed=frequency*wavelength

Question 21

which has the highest frequency visible light, infrared or uv

Answer 21

uv has the highest frequency

Question 22

what are uses of uv

Answer 22

uv can be used for security such as bank notes having uv markings

Question 23

what are the dangers of uv

Answer 23

causing sun burn and damaging eyes

Question 24

what has a higher wavelength x rays or gamma

Answer 24

x ray

Question 25

what are the 2 main uses of gamma

Answer 25

killing harmful bacteria in food or surgical tools and cancer treatment

Question 26

what is the main use of x rays

Answer 26

medical imaging

Question 27

what is ionisation

Answer 27

when an atom looses an electron

Question 28

what happens if ionisng happens to living cells

Answer 28

damage cells and potentially cause cancer

Question 29

what do people who work with radiation wear

Answer 29

saftey film badge that changed colour when exposed to radiation

Question 30

what is a differnce between uv and visible light

Answer 30

you cant see uv

Question 31

what can waves transfer

Answer 31

energy and information

Question 32

what type of waves carry information and how do they do this

Answer 32

carrier waves they does this by varying their amplitude

Question 33

how do em waves change properties

Answer 33

based on frequency and wavelength

Question 34

what transfers more energy ? shorter or higher wavelengths

Answer 34

shorter, as the frequency is higher, this means that more waves arrive in more time so more energy can be transfered. The downside to this is that the range is lower due to absorbtion by the atmosphere

Question 35

which has a higher frequency radio waves or microwaves

Answer 35

microwaves

Question 36

what can microwaves be used for

Answer 36

satelite communication

Question 37

what device converts sound into electrical signals and how does it work

Answer 37

microphone coverts sound into electricial singnals, these are then combined with a carrier waves in a transmitter, this creats a radio signal. A reciever then converts the radio waves back into an electric current witn the same frquency as the wave. A speaker then converts this into sound.

Question 38

are childrens or adults brains more effected by the use of mobile phones

Answer 38

mobile phones use microwaves signals, children have thinner skulls then adults meaning their brains might be more effected by mobile phone use

Question 39

what are optical fibres and what 2 parts of the em spectrum do they use

Answer 39

optical fibres are thin transparent fibres that are used to transmit signals by infrared and visible light

Question 40

why are optical fibres secure

Answer 40

signal is contained in fibire not the air

Question 41

why can optical fibres transfer more enegy then radio waves

Answer 41

optical fibrres uses ligtht which has a shorter wavelength there for higher frqeuency then radio waves meaning it can transfer more information

Question 42

do x rays of uv have longer wavelengths

Answer 42

uv

Question 43

what parts of your body block x rays

Answer 43

bones teeth metal inside body

Question 44

how does an x ray work

Answer 44

they have a film or detected that changes when x rays hit it

Question 45

how can you x ray soft tissue organs

Answer 45

fill them with a contrast medium that absorbs x rays

Question 46

how can you cover parts you dont want to x ray

Answer 46

cover them with lead plates

Question 47

what is a radiation dose

Answer 47

a measure of the damadge done to the body by ionising radiation

Question 48

what factores effect radiation dose

Answer 48

radiation type time exposed the energy per second absorbed

Question 49

what is dose measured in

Answer 49

sv

Question 50

what waves are used in ct scans

Answer 50

x-rays from differnt angles to created a 3d image