872320
Description
Flashcards by Lauren Robinson, updated more than 1 year ago
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Created by Lauren Robinson
almost 11 years ago
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| Question | Answer |
| An AC supply of electricity has a time period of 0.08s. What is the frequency? | 1/0.08 = 12.5 |
| What are the three wires in the three pin plug? What does each one do? | Live - alternates between a positive and negative high voltage Earth - Carries electricity to the earth if something is wrong Neutral - always neutral |
| How do the fuse and the earth wire work together? | FAULT develops in the wire SURGE in current melts fuse, cutting off the live supply and breaking the circuit ISOLATES the whole appliance so you can't get an electric shock ALSO prevents the risk of fire FSIA |
| How does an RCCB work? | It detects the difference in current and cuts off the power by opening a switch. Quicker than fuses and can be reused |
| What are the relative masses and charge of the 3 basic subatomic particles? | Particle mass charge Proton 1 +1 Electon 0 -1 Neutron 1 0 |
| What is an alpha particle? | 2 protons, 2 neutrons Overall positive charge Good at ionising Bad at penetrating |
| What is a beta particle? | 1 electron Overall negative charge Moderate at ionising Moderate at penetrating |
| What is a gamma ray? | An electromagnetic wave No charge Bad at ionising Good at penetrating |
| List two places where background radiation is increased | In coastal areas where there are lots of rocks Man made sources eg from nuclear weapons and nuclear waste |
| What occupations have an increased risk of exposure to radiation? | Commercial pilots Miners Nuclear industry workers Radiographers |
| What is the definition of half life? | Half life is the life taken for the number of nuclei in a radioactive sample (isotope) to halve. |
| Give an example of how gamma radiation can be used in medicine | In radiotherapy for cancer patients as it has a short half life, so kills the cancer cells without the patient being radioactive for too long |
| What materials can stop alpha, beta and gamma rays? | Alpha- paper (large so stopped easily) Beta- Aluminium Gamma- concrete or lead (very small) |
| What is the main environmental problem associated with nuclear power? | Often uses more energy than it releases |
| Give the main stages of the life cycle of a star around THE SAME size of our sun | 1) Protostar 2) Main sequence star 3) Red giant 4) White dwarf 5) Black dwarf |
| Give the main stages of the life cycle of a star much BIGGER than our sun | 1) Protostar 2) Main sequence star 3) Super red giant 4) Supernova 5) Neutron star OR black hole |
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