Answer:
D
Explanation:
I read about it in my Social studies textbook
The popular method used by researchers in usability study is a method called a direct observation
<h3>
What is a direct observation?</h3>
A direct observation refers to a method of collecting data where the researcher watches the subject in his or her natural setting.
The direct observation is also called observational study
In conclusion, the popular method used by researchers in usability study is a method called a direct observation
Read more about direct observation
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The continuous neutral-current rating be for an autotransformer used to create a three-phase, it must be sufficient to handle the maximum possible neutral unbalanced load. 450.5.
<h3 /><h3>What is meant by autotransformer?</h3>
A grounding autotransformer is used to create a three-phase, 4-wire distribution system from a three-phase, 3-wire ungrounded system.
A three-phase autotransformer is a special type in which common winding is shared by the high voltage and low voltage. Three-phase AC is supplied at primary and output is collected at secondary. Three phase autotransformer is used for such applications where a small voltage is used in the distribution system.
Autotransformers are frequently used in power applications to interconnect systems operating at different voltage classes, for example, 132 kV to 66 kV for transmission. Another application in industry is to adapt machinery built (for example) for 480 V supplies to operate on a 600 V supply.
To learn more about autotransformers refer to:
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