| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.92 |
| Score | 0% | 58% |
Which of the following is not an advantage of semiconductors over conductors?
a semiconductor conducts current better than a conductor |
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a semiconductor's conductivity can be varied under an external electrical field |
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materials to produce semiconductors are cheap and abundant |
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a semiconductor exhibits increased conductivity with increased temperatures |
A semiconductor is a material that has a limited ability to conduct electrical current with conductivity between that of an insulator and that of a conductor. Silicon, a cheap and abundant material, is the most used semiconductor material although other materials are used in the electronics components made from semiconductors. The primary advantages of a semiconductor over a conductor is that the conductivity of a semiconductor can be varied under an external electrical field giving engineers precise control over complex circuits and, unlike conductors like metals, a semiconductor's conductivity increases with increased temperatures.
What is the voltage of most household electrical systems in the United States?
110V |
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60Hz |
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220V |
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60V |
Most households use electricity with a voltage of 110V.
In electrical wiring, which of the following are proportional?
the diameter of the wire and the amount of the current |
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the length of the wire and the amount of the voltage |
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the length of the wire and the amount of the current |
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the diameter of the wire and the amount of the voltage |
Current flow through a wire increases the temperature of the wire. If too small a wire is used, the wire will heat up causing a loss in conductivity and possibly a fire. The thicker in diameter a wire is, the more current it can carry without overheating.
Which of the following allows encapsulating complex circuit designs for easier integration into electronic devices and machines?
parallel circuits |
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integrated circuits |
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series-parallel circuits |
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series circuits |
Circuits containing transistors are packaged into integrated circuit chips that allow encapsulating complex circuit designs (CPU, memory, I/O) for easier integration into electronic devices and machines.
A capacitor is often used for which of the following purposes?
to allow a small amount of current to control a large amount of current |
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to convert alternating current into direct current |
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as a primary power source |
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to maintain power in a circuit when the primary power source is disconnected |
Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.