electromagnetic waves Flashcards
what is a bi concave lense also known as
divering lens
what is a bi convex also know as
converging lens
what is a biconcave lens
makes parrel light rays diverge
what does converge mean
come together
what does diverge mean
spread out
what is a bi convex lens
makes parallel light rays converge
what is the focal length
the distnace betweem the focal point and the centre of the lens
what is the focal point
the point as which light tays converge after passing through a lens
what is power
a measure of how much a lens refracts light that passes through it
what is convering lens
a lens that s fatter in the middle than at the edges
what is divering lens
a lens that is thinner in the middle than at its edges
What is a real image
is an image that can be projected onto another surface
what type of lens can be used to create a real image
biconvex
can real images be projected onto a screen
yes
can virtual images be projected
onto a screen
what do divering lenses prouduce
virtual images
when you use a magnifying glass how do images appear
The image appears to be on the same side of the lens as
the object, is upright and magnified.
what do lens diagrams tell us about an image
a)Real /virtual
b)Magnified/ diminished/ same size
c)Inverted/ upright
what kind of animals can see ultraviolet light
bees and insect,it helps guide them to see pollen
are ultra violent waves short or long
short for our eyes to detect
what are elctromagnectic waves
transverdsde waves that travel at the speed of light in a vaccu, and transfer energy but not matter
what are three examples of electromagnetic waves
- ultgra violent
- infrared
- visbale light
what is a vaccum
empty space or a space with no air particles
any objectt that is warm emits..
infra red waves
anything where the frequency are too high to detect are what kind of electromagnetic waves
ultraviolet
anything where the frequency is too low to detect are what kind of electromagnetic waves
infrared
do radio waves have low or high frequency
low frequency,low wave length and low danger
how do we detect lenses
x ray telescope
how are mucro waves used
- communication and satellite transmissions
- micro waves are the way we communicate with phones
- transfer energy to water molecules to heat it from the inside
- communicate at very long distances because the wave is travelling to a staillite and then being re transmitted
how are radio waves used
- transmitting radio broadcastin
- communicate with space craft
- refracted by ionsphere
- long range commuication
how are infra red used
- communicate at short ranges
- transfer energy to food
- detect heat through night vision and security cameras
how is visble light used
- record images in cameras
- light reflects of surfaces
- capture light
what is an example where visble loight is used
- camera
- light blub
what is an example of radio waves
- satillates
- controllers
what is an exomple where infra red is used
- compuiters
- tv
- grill
explain how radio waves and microwaves are used for long communication
radio waves are refracted ionosphere which allows them to overcome the curvature of the earth traveling at long distances. microwaves are transmitted through the ionosphere and are received by satellites and the satellites then retransmits this to a receiver
ionosphere
is charged layer around the atmosphere
name three short em waves
ultra violet,x rays , gamma rays
what are the use of x rays
- are used in medical scanning ( to see broken bones )
- can pass through skin muscles and fat
-0- can’t pass through bones - bones absorb the xrays because they are dense
- the brighter the white is on the x-ray is the denser it is
- used in airports to scan luggage
- it is used for security scans in airports and metals are dense matriels so they absorb the x ray
-can use to detect leaks or broken pipes - the x-ray can pass through the break in the pipe, this is when the pipe is of dense material , good way to identify where a break in a pipe is
what are the use of ultra violet waves
- we can’t see it
- if we had a lamp, you won’t be able to see if the lamp breaks,
- if you had a banknote, you can use ultraviolet light to see if it is real or not and the uc is absorbing the ink and then emits visible
- can kill cells
in water treatment, all the water that Is clean goes through a machine where that shine ultraviolet light it to kill the bacteria and this stops diseases from passing
what are the use of gamma rays ?
is it high frequency or low frequency ?
what happens when are exposed to massive amounts of radiation
what happens when we are sterlizing medical equipment
what happens when you are buying fresh fruit ?
how do hospitals use gamma rays to treat patients ?
- high frequency
- gamma rays transfer more amount of wavelength because of their high frequency
- transfer huge amounts of energy
- when we are exposed to massive amounts of radiation, we die
- we can use gamma radiation to sterilize medical equipment
- when they sterilize them, they put them in a machine and because the gamma rays are powerful, anything that is alive
will be killed like bacteria and human cells - when you buy fresh fruit from the supermarket, on a convey belt it is blasted with gamma rays and it helps to kill any bacteria on that bacteria and stops it from going off as quickly . It extends their shelf-life
- we use gamma rays for treating and diagnosing patients
- in hospitals, they use gamma electromagnetic waves and this is when a patient is diagnosed with having a tumor for example cancer
- gamma rays can be used to diagnose tumors and to treat them
how can infra red waves be dangerous
can cause burns to skin
what is the realtionship between frequency and danger
the greater the frequency , the hreater the energy transferred by a wave. highfrequency waves are ionsing
name the non ionsing electro magnetic waves
radio waves,microwaves,infrared,visble light
name the ionsing waves
ultraviolet,xray,gamma rays
what part of the body absorbs ultra vioet
skin
what is the effect of ultravilet
- damages skin cells
- cause mutation in dna
- can lead to skin cancer
what part of the body absorb x rays
bones
what is the effect of x rays
- cause mutation in dna
- can lead to bone cancer
what is the effect of gamma rays
- ## kill cells
what is the effect of visbile light
temporary blindless
inthe investigating radiation core practicalwhat isthe aim
invistage how the nature of surfaces affect the amout of thermal energy radiated or absorbed
