| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.61 |
| Score | 0% | 72% |
Which of the following is a difference between a circuit breaker and a fuse?
all of these |
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a fuse responds more quickly than a circuit breaker |
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a fuse is cheaper than a circuit breaker |
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a circuit breaker can be reused |
Like fuses, circuit breakers stop current flow once it reaches a certain amount. They have the advantage of being reusable (fuses must be replaced when "blown") but respond more slowly to current surges and are more expensive than fuses.
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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electrically conductive materials have no resistive properties |
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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 |
Resistance is opposition to the flow of current. As resistance increases, current decreases as resistance and current are inversely proportional.
What is the primary difference between a rectifier and an inverter?
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 |
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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 |
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 watt is a unit of measurement for:
energy |
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frequency |
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resistance |
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power |
Electrical power is measured in watts (W) and is calculated by multiplying the voltage (V) applied to a circuit by the resulting current (I) that flows in the circuit: P = IV. In addition to measuring production capacity, power also measures the rate of energy consumption and many loads are rated for their consumption capacity. For example, a 60W lightbulb utilizes 60W of energy to produce the equivalent of 60W of heat and light energy.
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.