| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.13 |
| Score | 0% | 63% |
Which of the following is not true about a line drop?
it is a decrease in voltage between two points on a line |
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it is addressed by raising voltage and lowering current across the transmission line |
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it is caused by resistance |
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it is addressed by raising current and lowering voltage across the ransmission line |
Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances. A line drop is a decrease in voltage between two points on an electrical transmission line due to resistance in the line. A lower current and higher voltage across the line will help compensate for the line drop.
This circuit component symbol represents a(n):
DC source |
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transistor |
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transformer |
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AC source |
In contrast to the constant one-way flow of direct current, alternating current changes direction many times each second. Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances.
Resistance is opposition to which of the following?
conductance |
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current |
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voltage |
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impedance |
Resistance is opposition to the flow of current and is measured in ohms (Ω). One ohm is defined as the amount of resistance that will allow one ampere of current to flow if one volt of voltage is applied. As resistance increases, current decreases as resistance and current are inversely proportional.
An amplifier is most similar in function to which of the following:
capacitor |
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step-up transformer |
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step-down transformer |
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transistor |
An amplifier is a device that takes a small input signal and creates a larger output signal. This makes it most similar to a step-up transformer which takes a smaller input voltage and creates a larger output voltage.
Which of the following allows current to pass easily in one direction and blocks current in the other direction?
resistor |
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diode |
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inductor |
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capacitor |
A diode allows current to pass easily in one direction and blocks current in the other direction. Diodes are commonly used for rectification which is the conversion of alternating current (AC) into direct current (DC). Because a diode only allows current flow in one direction, it will pass either the upper or lower half of AC waves (half-wave rectification) creating pulsating DC. Multiple diodes can be connected together to utilize both halves of the AC signal in full-wave rectification.