| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.30 |
| Score | 0% | 66% |
Which of the following is a difference between a circuit breaker and a fuse?
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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all of these |
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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.
The valence shell of n insulator is how full of electrons?
empty |
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half full |
|
more than half full |
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less than half full |
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.
You would measure the amount of current through a circuit with a(n):
potentiometer |
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ammeter |
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battery |
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voltmeter |
Current is the rate of flow of electrons per unit time and is measured in amperes (A). An ammeter is used to measure the electric current in a circuit.
Which of the following is not a terminal on a transistor?
input |
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emitter |
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collector |
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base |
A transistor works by allowing a small amount of current applied at the base to control general current flow from collector to emitter through the transistor.
The valence shell of a semiconductor is how full of electrons?
more than half full |
|
half full |
|
less than half full |
|
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.