| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.13 |
| Score | 0% | 63% |
You would measure the amount of current through a circuit with a(n):
potentiometer |
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ammeter |
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voltmeter |
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battery |
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 converts electrical energy into another form of energy in an electrical circuit?
DC source |
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load |
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AC source |
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wiring |
A load is a source of resistance that converts electrical energy into another form of energy. The components of a microwave, for example, are loads that work together to convert household electricity into radation that can be used to quickly cook food.
What is the voltage of most household electrical systems in the United States?
60Hz |
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110V |
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60V |
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220V |
Most households use electricity with a voltage of 110V.
Which of the following allows DC to pass easily but resists the flow of AC?
capacitor |
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semiconductor |
|
transformer |
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inductor |
An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.
Which of the following allows current to pass easily in one direction and blocks current in the other direction?
capacitor |
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diode |
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resistor |
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inductor |
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.