Components are connected one after another. 1) the current is the same in each component. 2) adding the potential differences gives the total potential difference. 3) adding the resistances gives the total resistance.
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Parallel Circuits
Components are connected across the supply. 1) total current= sum of currents through SEPARATE components. 2) bigger resistance= smaller the current. Potential difference is the same across each component
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In the UK???
frequency = 50HZ voltage= 230 V
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What is a Period
time taken for 1 cycle
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Cables and Plugs
OUTER COVER: plastic/rubber. good electrical insulators. PINS: brass. good electrical conductor, hard, not rust or oxidise. WIRES: copper. good electrical conductor, bends easily
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What is alternating current????
current that keeps changing direction
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What is direct current?????
current that flows in one direction
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Metal case appliances must be......
Earthed to make the appliance safer
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Plastic cased appliances don't.......
Need to be earthed, double insulated and are connected to the supply with two- core cable
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Cables with different thickness...
Are used for different purposes. More current to be carried, the thicker the cable
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Electrical Issues
1) Faults may occur as a result of damage to sockets, plugs, cables or appliances. 2) equipment checked regularly. 3) avoid overloading sockets OVERHEATING & RISK OF FIRE. 4) handled safely
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Half Life
measures how quickly the radioactivity decreases. time taken for the count rate from the original isotope to fall to half its initial value.
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Ohms Law
Resistor is kept at a constant temperature, potential difference- current shows a straight line passing through; THIS MEANS the current is directly proportional to the potential difference across the resistor.
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Plum Pudding Model
Rutherford&Marsden; developed the model atom, 19th Century. Tested the model by using alpha particles.
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Fuse
melts if too much current. if live wire is faulty, current goes into the earth wire. LOW resistance ----> current goes UP ----> fuse BLOWS UP
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Early Universe
*created by the big bang *hot glowing ball of radiation *expanded, temperature fell *atoms formed *dust+gas pulled together by GRAVITATIONAL ATTRACTION to form STARS. *Group of stars ---> billion of galaxies ----> universe
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Nuclear Fusion
Forcing two nuclei close enough together so they form a single layer nucleus. *making two light nuclei collide at a very high speed. *energy is released in stars by this
Beta: deflected the most, due to mass. Alpha: deflected slightly and opposite to beta due to charge & mass. Gamma: no deflection; no charge
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Range.....
Alpha: stopped by paper/skin range a few cm in air. Beta: stopped by few mm aluminium range a meter in air. Gamma: stopped by a few cm of lead and few ft. of concrete. range many km in air: unlimited
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Gieger muller tube
Measures amount of radiation the sample has. INCREASED COUNT= MORE RADIOACTIVE THE SAMPLE IS
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Nuclear Fission
Splitting of an atomic nucleus. *URANIUM 235 + PLUTONIUM 239. nucleus splits into 2 small nuclei after nucleus absorbs neutron ---> 2 or 3 neutrons are emitted and energy released -----> chain of reaction occurs
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Other cards in this set
Card 2
Front
Components are connected across the supply. 1) total current= sum of currents through SEPARATE components. 2) bigger resistance= smaller the current. Potential difference is the same across each component
Back
Parallel Circuits
Card 3
Front
frequency = 50HZ voltage= 230 V
Back
Card 4
Front
time taken for 1 cycle
Back
Card 5
Front
OUTER COVER: plastic/rubber. good electrical insulators. PINS: brass. good electrical conductor, hard, not rust or oxidise. WIRES: copper. good electrical conductor, bends easily
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