| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.19 |
| Score | 0% | 64% |
Why does current in an electric circuit create heat?
current is naturally hot |
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voltage is naturally hot |
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the wire in the circuit burns when current passes through |
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heat is created when the current overcomes resistance in the wire |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.
| 96V 40A | |
| 12V 40A | |
| 48V 20A | |
| 96V 5A |
Connecting the 8 batteries in series multiplies their voltage while keeping their current the same yielding a 96V 5A configuration. Connecting the 8 batteries in parallel multiplies their current while keeping their voltage the same yielding a 12V 40A configuration. Using a series-parallel connection, 4 batteries can be connected in series and 4 can be connected in parallel resulting in a 48V 20A configuration.
A __________ electric current produces a magnetic field proportional to the amount of current flow.
high voltage |
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moving |
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stationary |
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low voltage |
A moving electric current produces a magnetic field proportional to the amount of current flow. This magnetic field can be made stronger by winding the wire into a coil and further enhanced if done around an iron containing (ferrous) core.
Which of the following statements about a capacitor is false?
to discharge a capacitor safely, use a high-wattage resistor comparable to the capacitance of the capacitor |
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you should always discharge any capacitors before working on an electronic circuit |
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it is safe to touch a capacitor with your hands as long as it is small |
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a capacitor remains charged even after the input voltage is removed |
The purpose of a capacitor is to retain electric charge and it will do so even after its input voltage is removed. After the input voltage is removed, the capacitor will slowly discharge but, depending on the size and characteristics of the capacitor, discharging could take from a few minutes to a few years. So, it's never safe to touch a capacitor with your hands and you should make sure to discharge any capacitors in a circuit before working on it using an appropriately high-wattage resistor or a capacitor discharge tool.
The most common circuit configuration is:
series-parallel |
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series |
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parallel |
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household |
Circuits are not limited to only series or only parallel configurations. Most circuits contain a mix of series and parallel segments. A good example is a household circuit breaker. Electrical outlets in each section of the house are wired in parallel with the circuit breaker for that section wired in series making it easy to cut off electricity to the parallel parts of the circuit when needed.