| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.45 |
| Score | 0% | 69% |
What is the frequency of most household electrical systems?
110Hz |
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60Hz |
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110V |
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60MHz |
Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances. Most households use electricity with a frequency of 60Hz.
The hertz is a unit of measurement for:
inductance |
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power |
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energy |
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frequency |
The hertz is a unit of measurement for frequency.
In an electrical circuit, resistors have fixed or __________ resistance.
dynamic |
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variable |
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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.
Which of the following statements about electrical resistance is true?
the less resistive the conductor is the slower electron flow will be |
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the more resistive the conductor is the slower electron flow will be |
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the more resistive the conductor is the faster electron flow will be |
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electrically conductive materials have no resistive properties |
Resistance is opposition to the flow of current. As resistance increases, current decreases as resistance and current are inversely proportional.
Which of the following converts electrical energy into another form of energy in an electrical circuit?
AC source |
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load |
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DC source |
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wiring |
A load is a source of resistance that converts electrical energy into another form of energy. The components of a microwave, for example, are loads that work together to convert household electricity into radation that can be used to quickly cook food.