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30 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is current? |
The flow of electrical charge |
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What is potential difference? |
The driving force that pushes the charge around |
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What is anything that slows down the flow called? |
Resistance |
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The equation that finds total charge: |
Q = I t
Q being charge I being current T being time |
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Name each component |
:) |
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What formula links potential difference and current? |
V = IR |
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What 4 factors effect resistance? |
Type of metal Thickness of wire Length of wire Temperature |
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What's special about ohmic conductors? |
They have a constant resistance, no matter what the current is |
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Describe a diode graph and explain why it's like this: |
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Describe a filament lamp graph and explain why it's like this: |
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Describe the graph of an ohmic conductors and explain it: |
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If you remove or disconnect a component that was in parallel what will it do to the others? |
Nothing |
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What happens to potential difference in parallel? |
Remains the same across all components |
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What happens to current in parallel? |
Shared |
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What effect does adding a resistor in parallel do to the total resistance? Why? |
Reduces it, because it gives the current another direction to go. This increases the total current that can go around the circuit , V = IR shows that if I goes up R goes down |
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When adding resistors to series / parallel what happens to the resistance, describe how this would look on a graph: |
Describe something like this? |
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Name the two types of electrical supply: |
Alternating current (AC) Direct current (DC) |
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What type of electricity comes through the mains supply and what voltage and frequency is it? |
AC 230V 50hz |
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What type of electricity do batteries use? |
DC |
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What three wires do most cables have (and what colour?)? |
Neutral wire - blue Live wire - brown Earth wire - green and yellow |
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What is the function of the three different wires in a cable and what voltage are they? |
Neutral wire - completes the circuit and carries away the current, 0V Live wire - provides the alternating potential difference (230V) Earth wire - for safety, stops appliance casing from becoming live,0V |
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Why can touching a live wire give you an electric shock? |
Because your body is at 0V so if you touch it a potential difference will be produced across your body and current will flow through. Any link between live and earth is dangerous if it has low resistance |
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Energy transferred in appliances is based on what? |
Power, for example a 200w kettle would take longer to heat up the same amount of water than a 300w kettle would |
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Write the equation linking energy transferred and power: |
E = Pt Aka ell Theo |
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Watts is a watt? (;)) (I.e. what is one watt = to) |
Watts = joules per second |
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Name the formula linking charge flow and potential difference: |
E = QV Q being charge flow |
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What are the two equations to calculate power? |
P = VI P = I^2 R (the second is the same as the first just with 'V=IR' replacing V) |
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Does the national grid have a really high voltage or current? Why? |
Voltage, because if the current was high the wires would heat up and that would cause resistance and loads of thermal energy would be lost to surroundings |
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What are the four steps to get electricity to your home (consumer being the last step) |
Power station Step up transformer Step down transformer Consumer |
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:) |
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