| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.71 |
| Score | 0% | 74% |
You would measure the amount of voltage between two points in a circuit with a(n):
ammeter |
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battery |
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voltmeter |
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reostat |
Voltage (V) is the electrical potential difference between two points. A voltmeter is used to measure the voltage between two points in a circuit.
Which of the following is not a characteristic of a step-up transformer?
the secondary voltage is higher than the primary voltage |
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increases voltage |
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has more turns in the secondary winding than in the primary winding |
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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.
| 23 Ω | |
| 73 Ω | |
| 70 Ω | |
| 210 Ω |
Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.
Solved for resistance, R = \( \frac{V}{I} \) = \( \frac{700}{10} \) = 70 Ω
Longer the electrical wires mean _______________ voltage drop.
diminishing |
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greater |
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lesser |
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complete |
Electrical wires have a certain amount of resistance per foot. A longer wire means more resistance and a greater voltage drop.
Silver and gold are among the most highly conductive elements. Why is copper used much more often as a conductor in electrical circuits?
copper is durable and relatively cheap |
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silver and gold are brittle |
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silver and gold are costly |
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all of these |
All conductors have resistance and the amount of resistance varies with the element. But, resistance isn't the only consideration when choosing a conductor as the most highly conductive elements like silver and gold are also more expensive and more brittle than slightly less conductive elements like copper. A balance needs to be struck between the electrical qualities of a material and its cost and durability.