| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.62 |
| Score | 0% | 72% |
From what energy do photovoltaic cells produce electrical energy?
sun |
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nuclear |
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magnetic |
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chemical |
A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.
An engineer who wants to document an electric circuit would create which of the following?
a blueprint |
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a matrix |
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a layout |
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a schematic |
A schematic is the proper name for a drawing of an electric or electronic circuit.
The watt is a unit of measurement for:
energy |
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power |
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frequency |
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resistance |
Electrical power is measured in watts (W) and is calculated by multiplying the voltage (V) applied to a circuit by the resulting current (I) that flows in the circuit: P = IV. In addition to measuring production capacity, power also measures the rate of energy consumption and many loads are rated for their consumption capacity. For example, a 60W lightbulb utilizes 60W of energy to produce the equivalent of 60W of heat and light energy.
Which of the following is a difference between a circuit breaker and a fuse?
a fuse is cheaper than a circuit breaker |
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all of these |
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a circuit breaker can be reused |
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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.
In an electrical circuit, resistors have fixed or __________ resistance.
parallel |
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dynamic |
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series |
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variable |
Resistors are used to limit voltage and/or current in a circuit and can have a fixed or variable resistance. Variable resistors (often called potentiometers or rheostats) are used when dynamic control over the voltage/current in a circuit is needed, for example, in a light dimmer or volume control.