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52 Cards in this Set
- Front
- Back
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What piece of equipment measures radioactivity? |
A Geiger Counter |
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What type of radiation has the most penetrating power? |
Gamma radiation |
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Voltage = ? |
Current × Resistance |
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How do you calculate work done? |
Work Done(joules) = Force × Distance |
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How do you calculate the total distance travelled in a velocity-time graph? |
Work out the area underneath the graph. |
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What isotope of plutonium is used in most nuclear power stations as fuel? |
Plutonium-239 |
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What uranium isotope is used as a fuel in nuclear power stations? |
Uranium-235 |
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How are stars formed? |
Gas and dust cloud collapse under the force of gravity beginning nuclear fusion. |
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What is nuclear fusion? |
Two nuclei joining to form one nucleus under immense heat and pressure. |
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How fast does beta radiation travel? |
Very fast (compared to an alpha particle) |
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Describe what happens to an atom with beta radiation. |
A neutron changes to a proton and releases an electron. |
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What is the life cycle of a star bigger than the sun? |
Protostar Main Sequence Star Red Supergiant Supernova Black Hole/Neutron Star |
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What is the life cycle for a star smaller than the sun? |
Protostar Main Sequence Star Red Giant White Dwarf Black Dwarf |
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What is nuclear fission? |
The splitting of a nucleus by a neutron which releases energy |
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What is an alpha particle? |
A helium nucleus. |
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What is a fuse? |
A component the breaks if the current flowing through a circuit is too high. |
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What are the 5 rules for a circuit? |
In a series circuit: - the current is the same everywhere - the voltage is shared between components In a parallel circuit: - the voltage is the same everywhere - the current is shared between the routes In all circuits: - total resistance = resistance of all the components |
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Why are seatbelts and airbags useful in saving the lives of motorists? |
They increase the time for a change in momentum to occur therefore reducing the force on the motorists. |
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What factors affect stopping distances? |
Drugs Distractions Road Surface Conditions e.g. icy Car Brake Conditions A driver's reaction time. |
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What is the difference between A.C and D.C? |
Alternating current moves in two directions and has a frequency. |
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How do most scientists believe the universe began? |
They believe that all matter expanded from one point. |
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What evidence is there for the big bang? |
Cosmic Microwave Background Radiation (CMBR) Red Shifted Galaxies |
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Why are pins in plugs usually copper? |
It is extremely unreactive and a good conductor of electricity. |
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Why does radioactive decay occur? |
Atoms want to become more stable. |
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What is the function of an earth wire? |
It gives the current a safe route to discharge and not do any harm in case of a fault. |
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What materials are used for plug cases? |
Plastics or any other good insulators. |
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What does a neutral wire do? |
Complete the circuit. |
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What does a live wire do? |
Supplies the potential difference. |
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How do you make an object more streamline? |
You reduce the surface area of the body so less of it is in contact with the air. This reduces the force of the air resistance therefore increasing the resultant force. |
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What force causes the most resistance for a moving object? |
Air resistance. |
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What is the supposed voltage of a UK mains supply? |
230V |
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If an object is moving at a steady speed what is the force on the object? |
0N |
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What are the units for work done? |
Joules |
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How do you work out the frequency of an A.C on an oscilloscope trace? |
1÷the period |
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How do you work out the period of a current on a oscilloscope trace? |
The amount of divisions in between two identical points e.g. two peaks or two troughs. |
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If two objects have the same charge will they attract or repel each other? |
Repel |
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What is the total momentum before and after a collision? |
The same or conserved. |
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What is the formula of momentum? |
Mass * Velocity |
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How did Geiger and Rutherford discover the modern atomic model? |
They fired alpha particles at a sheet of gold foil which was surrounded by a florescent sheet. The majority of the alpha particles passed through but some were deflected and some were fired back. They concluded that the particles were hitting something small, dense and charged. They had discovered the nucleus. |
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What happens when two electrically charged objects are brought together? |
They exert a force on each other. |
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What type of materials will become charged when they are rubbed together? |
Insulators |
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How many neutrons are released from nuclear fission? |
2 or 3 |
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Our sun is stable because the forces in it are... |
Balanced |
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In what stage of a star's cycle are elements heavier than iron found? |
Supernova |
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What is used instead of a fuse sometimes to protect an appliance or circuit? |
A residual current circuit breaker. (RCCB) |
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Which is faster, an RCCB or a fuse? |
RCCB |
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How far can alpha radiation travel in the air? |
Only a few centimeters. |
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How far can beta radiation travel in the air? |
Tens of centimeters. |
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Why do your hairs stand on end when you touch a Van de Graff. |
Your hairs become negatively charged so they repel each other. |
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What is the modern atomic model called? |
The Rutherford Model |
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Should radioactive tracers used for medical diagnosis have short or long half lives? |
Short |
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Describe what happens to a star after its main sequence to a giant star. |
The star runs out of hydrogen, cools and expands. |
