| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.26 |
| Score | 0% | 65% |
The joule is a unit of measurement for:
power |
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energy |
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resistance |
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capacitance |
The joule is a unit of measurement for energy.
Why is an insulator a poor conductor of electricity?
an insulator has few free electrons |
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an insulator is made of organic material |
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an insulator is made of inorganic material |
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an insulator has many free electrons |
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.
A capacitor is often used for which of the following purposes?
to maintain power in a circuit when the primary power source is disconnected |
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to allow a small amount of current to control a large amount of current |
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to convert alternating current into direct current |
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as a primary power source |
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.
Which of the following is not a purpose of a resistor in an electrical circuit?
limit the current in the circuit |
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moderate the heat in the circuit |
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multiply the current in the circuit |
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control the voltage in the circuit |
Resistors can be chosen in a wide variety of values to control the voltage in a circuit, limit the current, or moderate the heat produced by the components in the circuit.
| perpendicular | |
| series | |
| orthogonal | |
| parallel |
Connecting the 8 batteries in series multiplies their voltage while keeping their current the same yielding a 48V 5A configuration. Connecting the 8 batteries in parallel multiplies their current while keeping their voltage the same yieleding a 6V 40A configuration. Using a series-parallel connection, 4 batteries can be connected in series and 4 can be connected in parallel resulting in a 24V 20A configuration.