In the air conditioning field, variable frequency drive is ____ used to control the speed of blower motors.
a. never
b. often
c. always
d. rarely
b. often
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Which of the following is not one of the five categories of soil parent material?
A) glacial deposits B) loess deposits C) layer deposits D) organic deposits
Obtain the current i?(t) in the circuit in Fig. 18.44.
 figure 1.png)
A(n) ____________________ is a type of conduit body that allows for a 90-degree change of direction in a raceway path. It is often used to allow the service raceway to run from the meter socket, through the side of the house, and continue to the service equipment enclosure.
Fill in the blank(s) with the appropriate word(s).
Individual office furnishings of the freestanding type, or groups of individual office furnishings that are electrically connected, are mechanically contiguous, and do not exceed 30 ft when assembled, shall be permitted to connect to the building's electrical system by means of a ____.
A. single flexible cord and plug B. rigid raceway C. surge protector and concealed wiring D. dual flexible cable and panel board