13.1-13.3

Question 1

what do electromagnetic waves transfer

Answer 1

energy

Question 2

does wavelength get bigger or smaller as you go from left to right across the EM spectrum

Answer 2

smaller

Question 3

how do you calculate wave speed

Answer 3

wave speed=frequency x wavelength

Question 4

the shorter the wavelength the higher the…?

Answer 4

frequency

Question 5

what type of light is from the sun and ordinary lamps

Answer 5

white light

Question 6

what happens to wavelength in the light spectrum as you go from violet to red

Answer 6

increases

Question 7

what happens to light in a film camera

Answer 7

light is focused by the camera lens on to light sensitive film, the film then needs to be developed to see the full image

Question 8

what happens to light in a digital camera

Answer 8

the light is focused by the lens on to a sensor, this makes thousands of pixels , which creates the full image

Question 9

how does the temperature of an object effect the amount of infra red radiation it gives of

Answer 9

the hotter the object is the more infrared radiation it gives off

Question 10

what happens to infrared radiation around the body

Answer 10

it is absorbed by the skin and can damage, burn, or kill skin cells as it heats them up

Question 11

what type of wave do optical fibers use and why

Answer 11

optical fibers in communication use infrared radiation as it is absorbed less than visible light in the glass fibres

Question 12

what type of radiation do remote controls use to communicate with the main device and why

Answer 12

infrared radiation as they can be easily produced and detected electronically

Question 13

what are infrared scanners used for in hospitals

Answer 13

they are used to detect infrared radiation emitted from hot spots on the body surface, these hot areas can mean the tissues underneath in not healthy

Question 14

what type of cameras are used to see things in the dark

Answer 14

infrared cameras

Question 15

what does infrared radiation do to objects and what are the uses of this

Answer 15

it heats them up- this is used in electric heaters that emit infrared radiation to quickly warm up rooms and electric cookers that emit more infrared radiation then ordinary ones

Question 16

what is the wavelength of microwaves like in comparison to radio waves

Answer 16

shorter

Question 17

what are the uses of microwaves

Answer 17

communication e.g. satellite TV and mobile phone signals

Question 18

why does microwaves ovens heat food faster than ordinary ovens

Answer 18

the microwaves can penetrate into food and are absorbed by the water molecules in the food, heating it.

Question 19

what do radio wave frequencies range from

Answer 19

300,000Hz to 3000 million Hz

Question 20

what are radio waves used for

Answer 20

to carry radio, TV and mobile phone signals

Question 21

what are the hazarders of radio and microwaves

Answer 21

they penetrate peoples bodies and can heat up internal body parts

Question 22

what are carrier waves

Answer 22

waves that are used to carry a signal

Question 23

the shorter the wavelength of the carrier wave the…

Answer 23

more information they carry, the shorter range they have, the less they spread out

Question 24

what are microwaves used for

Answer 24

satellite phone and TV links and satellite TV broadcasting