Flashcards in Unit 2-Waves and Radiation Deck (53):
What are the two types of waves?
Transverse and Longitudinal
How do the particles move relative to the direction of travel in transverse waves?
At right angled
How do the particles move relative to the direction of travel in longitudinal waves?
They move Parallel to the direction of the travel
What is the definition of frequency and its unit of measurement?
The number of waves per second, Hertz(Hz)
What is the definition of wavelength and its unit of measurement?
The distance from one point on a wave to the corresponding point on the next wave, Metres(m)
What is the definition of amplitude and its unit of measurement?
The height of a wave from middle to top, Metres(m)
What is the definition of period and its unit of measurement?
The time for one complete wave to pass a point, Seconds(s)
What is the definition of wave speed and its unit of measurement?
The speed of the wave, (m/s)
How do you work out the period?
What is diffraction?
Diffraction is the bending of waves round objects
How loud is a normal conversation?
What is refraction?
When light passes between two mediums
What happens to light when it passes from a high density medium to a low density medium?
The waves speed up
What happens to light when it passes from a low density medium to a high density medium?
The waves slow down
A convex lens..
A concave lens...
Power of a lens equation?
Name the different waves of the electromagnetic spectrum in order from lowest frequency?
Radio, Microwave, Infrared, Visible light, Ultraviolet, X-ray and Gamma rays
In the electromagnetic spectrum, as the frequency increases....
The wavelength decreases
Name 1 example for the following categories for Radio waves: typical source, application, detector, possible hazards.
PH-Cancer, leukaemia and other disorders
Name 1 example for the following categories for Microwaves: typical source, application, detector, possible hazards.
TS-Microwave ovens, Stars, mobile phones
Detector-Radar detector dishes, diode probe
PH-Heating of body tissue, cataracts
Name 1 example for the following categories for Infrared waves: typical source, application, detector, possible hazards.
TS-The sun, remote controls, heat emitting objects
Application-heat source, night vision cameras, medical diagnostics
Detector-Thermometer, thermopile, phototransistor
PH-Sun stroke, dehydration
Name 1 example for the following categories for Visible light: typical source, application, detector, possible hazards.
TS-The sun, light bulbs
Application-optical fibres, medical treatment
Detector-eye, photodiodes, LDR, phototransistors
Name 1 example for the following categories for Ultraviolet rays: typical source, application, detector, possible hazards.
TS-The sun, UV lamps
Application-Helps body produce Vitamin D, disinfectant, dental treatment
Detector-Some materials fluoresce, UV photodiode
Name 1 example for the following categories for X-rays: typical source, application, detector, possible hazards.
TS- fast moving electrons colliding with metal targets, x-ray machine
Application-Medical imaging and diagnostic, analysis of atoms structures
Detector-X-ray darken photographic film, Geiger-Muller tube and counter
PH-severe burns, cancer, leukaemia, and cataracts
Name 1 example for the following categories for Gamma Rays: typical source, application, detector, possible hazards.
TS- Radioactive substances, nuclear reactors
Application-Medical diagnostic, sterilisations of medical instruments
Detector- Geiger-Muller tube and counter
What are the three types of radiation and their Greek sign?
What is Alpha radiation?
Alpha radiation is a helium nucleus made up of two protons and two neutrons.
What is Beta radiation?
Beta radiation is high speed electrons and is negatively charged
What is Gamma radiation?
Gamma radiation is gamma rays which are apart of the electromagnetic spectrum.
What can alpha radiation be absorbed by?
5 cm of a piece of paper
What can beta radiation be absorbed by?
Few millimetres of aluminium
What can gamma radiation be absorbed by?
A few centimetres of the lead or a few metres of concrete
Which natural sources give off radiation?
Rocks and soil, radon gases but particularly from granite, carbon potassium irons in our body, cosmic rays from outer space
Name some artificial sources of radiation
X-ray machines, radionuclides, nuclear waste from power stations, fallout from nuclear weapons testing
What are some medical applications for radiation?
X-rays, scans, cancer treatment,
What are some industrial applications for radiation?
detecting leaks, quality insuring welding,
What is the equation for absorbed dose?
What is the equation for equivalent dose?
What is the definition of half life?
The half life is the time taken for the activity of a radioactive source for the half of his previous value
What are the two types of nuclear reactions
Fission and fusion
What are the two types of nuclear fission
Induced fission and spontaneous fission
What is induced fission?
Induced fission is when a reaction is started when a slow neutron collides with a uranium nucleus making it unstable
Explain the process of an uncontrolled fission reaction?
The neutrons released by the first reaction collide with other uranium 235, which releases more energy and more neutrons, causing an uncontrolled reaction.
What is nuclear fusion?
Nuclear fusion is when two or more nuclei combine to form an element with different mass numbers. This is the opposite of nuclear fission.
Explain the process to use to obtain energy from nuclear power.
The heat released by the nuclear reaction is used to produce steam in the heat exchanger, this steam is used to turn the turbine which then turns the generator producing electrical energy.
What are some positives for using nuclear fuel?
Nuclear power stations produce a large amount of energy for a small amount of fuel. There are no CO2 and SO2 emissions from power stations.
What are some of the arguments against nuclear fuel?
Nuclear waste has to be stored securely for a very long time.
What are some biological effects of radiation?
Radiation can kill or damage cells. If the DNA of the cell is altered it can grow into a tumour
What are some environmental hazards of radiation?
All living things plants, animals as well as humans are affected by radiation. Very high doses can be fatal, large doses can cause sickness and mutations