| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.64 |
| Score | 0% | 73% |
The valence shell of a semiconductor is how full of electrons?
empty |
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more than half full |
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less than half full |
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half full |
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.
Which of the following will increase the magnetic field produced by the electric current in a wire?
wind the wire into a coil |
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construct the wire from conductive material |
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wrap the wire around a ceramic core |
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construct the wire from insulative material |
A moving electric current produces a magnetic field proportional to the amount of current flow. This magnetic field can be made stronger by winding the wire into a coil and further enhanced if done around an iron containing (ferrous) core.
This circuit diagram represents a(n):
series-parallel circuit |
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parallel circuit |
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series circuit |
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open circuit |
A series circuit has only one path for current to flow. In a series circuit, current (I) is the same throughout the circuit and is equal to the total voltage (V) applied to the circuit divided by the total resistance (R) of the loads in the circuit. The sum of the voltage drops across each resistor in the circuit will equal the total voltage applied to the circuit.
The hertz is a unit of measurement for:
energy |
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inductance |
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frequency |
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power |
The hertz is a unit of measurement for frequency.
Which of the following is a difference between a circuit breaker and a fuse?
a circuit breaker can be reused |
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a fuse is cheaper than a circuit breaker |
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all of these |
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a fuse responds more quickly than a circuit breaker |
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.