| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.43 |
| Score | 0% | 69% |
In an electronic circuit, a thermocouple can be used to:
open or close a circuit at a designated temperature |
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keep the circuit at a designated safe temperature |
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link the temperature of one component in the circuit to that of another component in the circuit |
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increase or decrease the temperature of a component in the circuit |
A thermocouple is a temperature sensor that consists of two wires made from different conductors. The junction of these two wires produces a voltage based on the temperature difference between them and can be used like a switch to open or close the circuit at a designated temperature.
Electrons will flow as current from areas of __________ potential (concentration of electrons) to areas of __________ potential.
low, low |
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high, low |
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low, high |
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high, high |
Voltage (V) is the electrical potential difference between two points. Electrons will flow as current from areas of high potential (concentration of electrons) to areas of low potential. Voltage and current are directly proportional in that the higher the voltage applied to a conductor the higher the current that will result.
| 72 Ω | |
| 140 Ω | |
| 71.5 Ω | |
| 70 Ω |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Solved for resistance, R = \( \frac{V}{I} \) = \( \frac{350}{5} \) = 70 Ω
Why does current in an electric circuit create heat?
heat is created when the current overcomes resistance in the wire |
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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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current is naturally hot |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.
From what energy do photovoltaic cells produce electrical energy?
magnetic |
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chemical |
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sun |
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nuclear |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.