| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.39 |
| Score | 0% | 68% |
| 103 Ω | |
| 50 Ω | |
| 150 Ω | |
| 100 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 = \( \frac{V}{I} \) = \( \frac{950}{9.5} \) = 100 Ω
Why does current in an electric circuit create heat?
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 |
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voltage is naturally hot |
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current is naturally hot |
Current in an electric circuit creates heat when the current overcomes resistance in the wire.
The valence shell of n insulator is how full of electrons?
more than half full |
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half full |
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empty |
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less than half full |
Insulators have valence shells that are more than half full of electrons and, as such, are tightly bound to the nucleus and difficult to move from one atom to another.
Which of the following is the same for each branch of a parallel circuit?
resistance |
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power |
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current |
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voltage |
In a parallel circuit, each load occupies a separate parallel path in the circuit and the input voltage is fully applied to each path. Unlike a series circuit where current (I) is the same at all points in the circuit, in a parallel circuit, voltage (V) is the same across each parallel branch of the circuit but current differs in each branch depending on the load (resistance) present.
In an electrical circuit, resistors have fixed or __________ resistance.
variable |
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dynamic |
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parallel |
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series |
Resistors are used to limit voltage and/or current in a circuit and can have a fixed or variable resistance. Variable resistors (often called potentiometers or rheostats) are used when dynamic control over the voltage/current in a circuit is needed, for example, in a light dimmer or volume control.