2314298
Description
Flashcards by Michael Priest, updated more than 1 year ago
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Created by Michael Priest
about 9 years ago
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| Question | Answer |
| Which appliances need earthing? | Appliances with metal cases |
| Describe the action of a circuit breaker (RCCB) | Difference in current between the live and neutral causes the circuit breaker to 'trip' and break the circuit |
| Name the 3 types of radiation | alpha, beta and gamma |
| Which type of radiation is most penetrating? | gamma |
| Which type of radiation is most ionising? | alpha |
| Which type(s) of radiation are affected by magnetic fields? | alpha and beta |
| List the types of radiation in order of speed (fastest to slowest) | gamma, beta, alpha |
| What is the potential difference of the mains electricity supply in the UK? | 230 Volts |
| What is the frequency of the mains electricity supply in the UK? | 50 Hertz |
| Describe the forces in a star in the Main Sequence | balanced |
| What stage of a star happens after Main Sequence for a star like the Sun | Red Giant |
| Describe the possible end of a star much bigger than the Sun | Neutron star or black hole |
| Describe the action of a fuse | It melts when too much current passes through it |
| What is meant by 'direct current' | Current passes in one direction only |
| What is meant by 'alternating current' | Current is constantly reversing direction |
| Describe the structure of a 3 pin plug | Plastic case Brass pins Plastic cable grip Fuse of correct value |
| Describe the structure of a 3 core cable | Live, neutral and earth wires which are insulated Live = brown Neutral = blue Earth = green + yellow |
| Explain how earthing protects users of appliances with metal cases | Higher than normal current passes from live to earth Fuse melts Breaking the circuit Stopping the case being live |
| What is meant by 'power' | The rate of energy transfer |
| P = E / t P = power, E = energy, t = time State the correct units | P = Watts E = Joules t = seconds |
| P = I x V P = power, I = current, V = potential difference State the correct units | P = Watts I = Amps V = Volts |
| E = V x Q E = energy, V = potential difference, Q = charge State the correct units | E = Joules V = Volts Q = Coulombs |
| Describe the structure of an atom | Nucleus consisting of protons and neutrons, orbiting electrons |
| State the charges of the components of an atom | Protons = +1 Neutrons = 0 Electrons = -1 |
| State two sources of background radiation | Nuclear weapons testing Cosmic rays |
| What is an ion? | An atom that has lost / gained an electron |
| What is an isotope? | An atom with the same number of protons, but a different number of neutrons |
| What is an alpha particle? | 2 protons, 2 neutrons |
| What is a beta particle? | A high speed electron |
| What is a gamma ray? | Electromagnetic radiation |
| Why are alpha, beta and gamma radiation dangerous? | They ionise atoms, which damages cells and causes cancer |
| What is meant by 'half life'? | The time it takes for the radiation emitted by a source to reach half the original level |
| What is nuclear fusion? | The joining together of two light nuclei with the release of energy |
| What is nuclear fission? | The splitting of a nucleus by absorbing a neutron with the release of energy (and 2 or 3 neutrons) |
| Name a nuclear fuel | Uranium (235) or Plutonium (239) |
| What is meant by 'chain reaction' | At least one neutron from a fission reaction goes on to cause a further fission |
| For a star like the Sun, what stage comes before the white dwarf stage? | Red Giant |
| Elements heavier than iron are produced in which stage of a star's life cycle? | Supernova |
| Name one element that is formed in the core of a star | Helium (could have anything up to iron) |
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