Your Results | Global Average | |
---|---|---|
Questions | 5 | 5 |
Correct | 0 | 3.64 |
Score | 0% | 73% |
Which of the following is the formula for calculating electrical power?
\(P = {I \over V}\) |
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P = IV |
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\(P = {V \over I}\) |
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P = I2V |
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.
Why is an insulator a poor conductor of electricity?
an insulator is made of organic material |
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an insulator has many free electrons |
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an insulator is made of inorganic material |
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an insulator has few free electrons |
Insulators have valence shells that are more than half full of electrons and, as such, are tightly bound to the nucleus and difficult to move from one atom to another.
If an electrical circuit is interrupted, which of the following will result?
closed circuit |
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short circuit |
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parallel circuit |
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open circuit |
A closed circuit is a complete loop or path that electricity follows. It consists of a source of voltage, a load, and connective conductors. If the circuit is interrupted, if a wire is disconnected or cut for example, it becomes an open circuit and no electricity will flow.
280 W | |
840 W | |
560 W | |
282 W |
A __________ electric current produces a magnetic field proportional to the amount of current flow.
high voltage |
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low voltage |
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stationary |
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moving |
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.