| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.52 |
| Score | 0% | 70% |
Which of the following will increase the magnetic field produced by the electric current in a wire?
wrap the wire around a ceramic core |
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wind the wire into a coil |
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construct the wire from conductive material |
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construct the wire from insulative material |
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.
Which of the following will help to prevent a short circuit?
fuse |
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transistor |
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diode |
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resistor |
Fuses are thin wires that melt when the current in a circuit exceeds a preset amount. They help prevent short circuits from damaging circuit components when an unusually large current is applied to the circuit, either through component failure or spikes in applied voltage.
Which of the following statements about electrical resistance is true?
electrically conductive materials have no resistive properties |
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the more resistive the conductor is the faster electron flow will be |
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the more resistive the conductor is the slower electron flow will be |
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the less resistive the conductor is the slower electron flow will be |
Resistance is opposition to the flow of current. As resistance increases, current decreases as resistance and current are inversely proportional.
Which of the following is the same for each branch of a parallel circuit?
power |
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resistance |
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voltage |
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current |
In a parallel circuit, each load occupies a separate parallel path in the circuit and the input voltage is fully applied to each path. Unlike a series circuit where current (I) is the same at all points in the circuit, in a parallel circuit, voltage (V) is the same across each parallel branch of the circuit but current differs in each branch depending on the load (resistance) present.
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 is cheaper than a circuit breaker |
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a fuse responds more quickly 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.