| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.94 |
| Score | 0% | 59% |
The conversion of alternating current (AC) into direct current (DC) is called:
reactance |
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capacitance |
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inductance |
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rectification |
A diode allows current to pass easily in one direction and blocks current in the other direction. Diodes are commonly used for rectification which is the conversion of alternating current (AC) into direct current (DC). Because a diode only allows current flow in one direction, it will pass either the upper or lower half of AC waves (half-wave rectification) creating pulsating DC. Multiple diodes can be connected together to utilize both halves of the AC signal in full-wave rectification.
| 15V 150A | |
| 300V 300A | |
| 150V 15A | |
| 75V 75A |
Connecting the 10 batteries in series multiplies their voltage while keeping their current the same yielding a 150V 15A configuration. Connecting the 10 batteries in parallel multiplies their current while keeping their voltage the same yielding a 15V 150A configuration. Using a series-parallel connection, 5 batteries can be connected in series and 5 can be connected in parallel resulting in a 75V 75A configuration.
Which of the following is not an advantage of semiconductors over conductors?
a semiconductor's conductivity can be varied under an external electrical field |
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a semiconductor exhibits increased conductivity with increased temperatures |
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a semiconductor conducts current better than a conductor |
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materials to produce semiconductors are cheap and abundant |
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.
Why is an insulator a poor conductor of electricity?
an insulator is made of inorganic material |
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an insulator is made of organic material |
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an insulator has few free electrons |
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an insulator has many free electrons |
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.
A transformer utilizes an inductor to increase or decrease what in a circuit?
resistance |
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current |
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load |
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voltage |
A transformer utilizes an inductor to increase or decrease the voltage in a circuit. AC flowing in a coil wrapped around an iron core magnetizes the core causing it to produce a magnetic field. This magnetic field generates a voltage in a nearby coil of wire and, depending on the number of turns in the wire of the primary (source) and secondary coils and their proximity, voltage is induced in the secondary coil.