| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.58 |
| Score | 0% | 72% |
You would measure the amount of current through a circuit with a(n):
ammeter |
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battery |
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voltmeter |
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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.
A capacitor is often used for which of the following purposes?
as a primary power source |
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to convert alternating current into direct current |
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to allow a small amount of current to control a large amount of current |
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to maintain power in a circuit when the primary power source is disconnected |
Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.
From what energy do photovoltaic cells produce electrical energy?
magnetic |
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nuclear |
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chemical |
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sun |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.
Electrons will flow as current from areas of __________ potential (concentration of electrons) to areas of __________ potential.
high, low |
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low, low |
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high, high |
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low, high |
Voltage (V) is the electrical potential difference between two points. Electrons will flow as current from areas of high potential (concentration of electrons) to areas of low potential. Voltage and current are directly proportional in that the higher the voltage applied to a conductor the higher the current that will result.
The conductivity of an element depends on how many electrons occupy which electron shell?
outer |
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inner |
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middle |
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first |
All electricity is the movement of electrons which are subatomic particles that orbit the nucleus of an atom. Electrons occupy various energy levels called shells and how well an element enables the flow of electrons depends on how many electrons occupy its outer (valence) electron shell.