| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.32 |
| Score | 0% | 66% |
What kind of diode allows current to flow in the opposite direction once a certain voltage threshold is reached?
zener diode |
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v-type diode |
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light emitting diode |
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standard diode |
A diode allows current to pass easily in one direction and blocks current in the other direction. A zener diode is a diode which allows current to flow in one direction as normal and will also allow current flow in the reverse direction when the voltage is above a certain value. This value is called the breakdown voltage.
Resistance is opposition to which of the following?
conductance |
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voltage |
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impedance |
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current |
Resistance is opposition to the flow of current and is measured in ohms (Ω). One ohm is defined as the amount of resistance that will allow one ampere of current to flow if one volt of voltage is applied. As resistance increases, current decreases as resistance and current are inversely proportional.
Which of the following can conduct electricity under some conditions but not others?
insulator |
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semiconductor |
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resistor |
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conductor |
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.
What is the primary difference between a rectifier and an inverter?
a rectifier converts a DC input to AC while an inverter converts an AC input to DC |
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a rectifier strips out the DC portion of electricity while an inverter strips out the AC portion |
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a rectifier strips out the AC portion of electricity while an inverter strips out the DC portion |
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a rectifier converts an AC input to DC while an inverter converts a DC input to AC |
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.
The valence shell of a semiconductor is how full of electrons?
less than half full |
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half full |
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more than half full |
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empty |
Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.