| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.46 |
| Score | 0% | 69% |
Which of the following is not a purpose of a resistor in an electrical circuit?
multiply the current in the circuit |
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moderate the heat in the circuit |
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control the voltage in the circuit |
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limit the current 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.
Which of the following is a difference between a circuit breaker and a fuse?
a circuit breaker can be reused |
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all of these |
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a fuse responds more quickly than a circuit breaker |
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a fuse is cheaper 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.
You would measure the amount of current through a circuit with a(n):
potentiometer |
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ammeter |
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battery |
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voltmeter |
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 is not a characteristic of a step-up transformer?
has more turns in the secondary winding than in the primary winding |
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increases voltage |
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the secondary voltage is higher than the primary voltage |
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the primary voltage is higher than the secondary voltage |
As their names indicate, a step-up transformer is used to step up or increase voltage and a step-down transformer is used to step down or decrease voltage. In a step-up transformer, the secondary voltage is higher than the primary voltage and it has more turns in the secondary winding than in the primary winding.
One of the lights on your Christmas tree burns out and this causes the rest of the lights connected to that strand to go dark. How are the lights in that strand connected?
series |
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perpendicular |
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series-parallel |
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parallel |
Lights connected in series form a chain with each light connecting to adjacent lights via one wire. Therefore, if one of the lights burns out and breaks the series, none of the other lights will receive power and they'll go dark. Lights connected in parallel each connect to the positive and negative nodes of the power source and would not go dark if one of their neighbors burnt out.