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20 Cards in this Set
- Front
- Back
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Where does the electric current flow from? |
The negative end of the cell to the positive end. |
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Facts about a series circuit? |
It has no branches and the current can only flow in one path. |
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Is current used up in a circuit? |
No. In a series circuit, the current is the same way all around. |
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Does a parallel circuit contain branches? |
Yes. Some of the current passes through both of the branches. |
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In parallel circuits, what does the current in the branches add up to? |
The total current leaving the cell. |
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What does charge flow (C) equal? |
Current (A) x Time (s). |
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What does Energy Transferred (J) equal? |
Charge (C) x Potential difference (V) |
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What is the total p.d. across both lamps the same as? |
The p.d. across the cell. |
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What is the potential difference across each component in parallel circuits? |
The same. |
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What does Resistance (ohms) equal? |
Potential difference (V) ÷ current (A). |
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What will the resistance only stay constant if? |
The temperature is constant. |
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Why is the current through a filament lamp not directly proportional to the p.d.? |
Because the filament gets hot, which causes the resistance to increase. |
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How does the current through a diode flow? |
In one direction only as the diode has a very high resistance in the reverse direction. |
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When does the resistance of a thermistor decrease? |
When the temperature increasesm |
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What are diodes extremely useful for? |
Controlling the flow of current in circuits. |
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What are LEDS? |
An extremely energy-efficient source of light. |
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Resistors in series .... |
add together. |
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What is the total resistance of two resistors in parallel less than? |
The resistance of the smallest individual resistor. |
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What would it mean if the current has increased but the p.d. hasn't changed? |
The total resistance must have decreased. |
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What does energy (J) equal? |
Power (w) x time (s). |
