| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.24 |
| Score | 0% | 65% |
You would measure the amount of current through a circuit with a(n):
voltmeter |
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battery |
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ammeter |
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potentiometer |
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.
The voltage output of a transformer primarily depends on which of the following?
the number of turns in the wire of the coils |
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the diameter of the wire in the coils |
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the diameter of the coils |
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the conductor used for the wire in the coils |
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.
Which of the following will increase the magnetic field produced by the electric current in a wire?
construct the wire from insulative material |
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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 |
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.
In metals, increasing the temperature typically _____________ conductivity.
decreases |
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does nothing to |
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increases |
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eliminates |
All conductors have resistance and the amount of resistance varies with the element. Metals exhibit increased resistance (and, therefore, lower conductivity) as their temperature increases.
The hertz is a unit of measurement for:
energy |
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frequency |
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inductance |
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power |
The hertz is a unit of measurement for frequency.